San Francisco's Exploratorium offers free admission to the public on the first Wednesday of every month.

Housed within the walls of the Palace of Fine Arts in the Marina District, the Exploratorium boasts more than 400 interactive science, art, and human perception exhibits for kids of all ages.

Also offering public presentations such as hands-on workshops, lectures, performances, films, and other special events, the museum aims to create a culture of learning through innovative environments, programs, and tools that help people nurture their curiosity about the world around them.

San Francisco's most visited museums offer FREE admission on the first Tuesday of every month. Take advantage of Free Museum Tuesdays at:

Conservatory of Flowers
Located in Golden Gate Park, the Conservatory of Flowers boasts almost 2,000 plant species in five immersive galleries. From tropical flowers to giant water lilies, the conservatory is a lush and diverse living museum for all ages.

de Young Museum
Founded in 1895 in San Francisco's Golden Gate Park, the de Young boasts a state-of-the-art new facility that integrates art, architecture, and the natural landscape in one multi-faceted destination. The museum showcases collections of American art from the 17th through the 20th centuries, and art of the native Americas, Africa, and the Pacific. Admission fees to special exhibits still apply.

Museum of Craft and Folk Art
As the only folk art museum in Northern California, the museum is known for a rich offering of focused and unique exhibitions of traditional and contemporary folk art and craft from around the world, demonstrating how folk art, contemporary craft, and fine art are all part of the same continuum.

Palace of the Legion of Honor
Built to commemorate Californian soldiers who died in World War I, the Legion of Honor is a beautiful Beaux-arts building located in San Francisco's Lincoln Park. Displaying an impressive collection of 4,000 years worth of ancient and European art in an unforgettable setting overlooking the Golden Gate Bridge, the Legion is also home to an early cast of Rodin's famous "Thinker" sculpture. Admission fees to special exhibits still apply.

San Francisco Museum of Modern Art
Located in downtown San Francisco, SFMOMA was the first museum on the West Coast devoted solely to 20th century art. Opened in 1935 to "explore compelling expressions of visual culture," the permanent collection comprises more than 25,000 works of modern and contemporary art, including photography, painting, sculpture, media arts, architecture, and design. Admission fees to special exhibits still apply.

Yerba Buena Center for the Arts
YBCA presents contemporary art from the Bay Area and around the world that reflects the profound issues and ideas of our time, expands the boundaries of artistic practice, and celebrates the diversity of human experience and expression.

For more than 20 years sea music enthusiasts have gathered at San Francisco's Hyde Street Pier on the historic tall ships C. A. Thayer and Balclutha to sing chanteys and other sea songs.

This free event, which takes place the first Saturday of every month, has garnered a loyal following, drawing 80 to 200 people monthly.

Hear California history come alive with chanteys that describe the perils of San Francisco's Barbary Coast, the dangers of rounding Cape Horn, cruel ship officers, the joys and curse of drink, and hopes for riches during the Gold Rush.

Be sure to bring a mug for complimentary apple cider!

Reservations required; call (415) 561-7171.

The Asian Art Museum of San Francisco offers free admission to all visitors on the first Sunday of every month.

One of the largest museums in the Western world devoted exclusively to Asian art, the Asian Art Museum collection spans 6,000 years of history and includes 17,000 objects, from tiny jades to monumental sculptures, paintings, porcelains and ceramics, lacquers, textiles, furniture, arms and armor, puppets, and basketry.

The collection galleries are divided into seven geographic regions: South Asia; the Persian World and West Asia; Southeast Asia; the Himalayas and the Tibetan Buddhist World; China; Korea; and Japan. Winding through all the galleries are three major themes: the development of Buddhism; trade and cultural exchange; and local beliefs and practices.

Join your guide Henry for an extensive walk through the streets (and over the hills) of San Francisco.

Enjoy the sights of the city as you wander through neighborhoods such as Russian Hill, Nob Hill, Chinatown, North Beach, and Telegraph Hill. See Lombard Street, Coit Tower, and some of the oldest homes and hidden gardens in the city.

This event is open to all guests at our three San Francisco hostels. Please sign up in advance.

Most Thursday nights, the California Academy of Sciences opens its doors after hours for NightLife.

Adults have a chance to explore the museum at night in a whole new light, as they dance to some of San Francisco's most popular DJs, enjoy food and cocktails, and mingle while perusing the Academy's world-class exhibits and getting up close and personal with aquarium critters.

Take in some knowledge with your libations -- each week features provocative science programming and a few surprises.

Meet your guide David at the San Francisco Downtown Hostel for a free historical tour of downtown San Francisco.

Learn about Union Square, Chinatown, Nob Hill, and other downtown landmarks. Don't forget your camera!

This event is open to all guests at our three San Francisco hostels. Please sign up in advance.

Join your tour guide Joe for an evening excursion to the San Francisco Museum of Modern Art.

Located in downtown San Francisco, SFMOMA was the first museum on the West Coast devoted solely to 20th century art. Opened in 1935 to "explore compelling expressions of visual culture," the permanent collection comprises more than 25,000 works of modern and contemporary art, including photography, painting, sculpture, media arts, architecture, and design.

SFMOMA offers half-price admission and extended hours every Thursday starting at 6 p.m., making this the perfect chance to soak up some culture with your fellow hostellers.

This event is open to all guests at our three San Francisco hostels. Please sign up in advance.

San Francisco City Guides offer free historical and architectural walking tours of San Francisco's most famous (or, in some cases, infamous) districts, as well as some of its more hidden neighborhoods.

Approximately 30 different walks are offered each month, year-round, rain or shine. Walkers meet at the place and time designated in the current tour schedule. No reservations are required.

Join your fellow hostellers for a trip to one of San Francisco's oldest and most captivating neighborhoods: Chinatown.

Though it's only a few blocks away from the San Francisco Downtown Hostel, Chinatown is another world unto itself, bustling with shops and buzzing with people. Explore hidden alleyways, sip various Chinese teas, see mysterious historic temples, and visit the famous San Francisco Fortune Cookie Factory.

This event is open to all guests at our three San Francisco hostels. Please sign up in advance.

Baseball is the ultimate American pastime, and $2 tickets are pretty hard to beat. Go to any Wednesday home game played by the Oakland A's for $2, and save room for food -- hot dogs are just $1 each!

The A's play on the other side of the Bay at Oakland's Coliseum stadium, which is about a 20-minute BART ride from downtown San Francisco. From the BART station, you can walk directly into the stadium.

**UPDATE: Tickets sell out quickly. You must order them online or by phone, (877) 493-2255, or print this page to get the discount at the door.**

The Wednesday home game schedule is:

4/7 - Oakland A's versus Seattle Mariners @ 7 p.m.

4/21 - vs. New York Yankees @ 7 p.m.

5/5 - vs. Texas Rangers @ 12:30 p.m.

5/19 - vs. Detroit Tigers @ 7 p.m.

6/9 -  vs. LA Angels @ 7 p.m.

6/23 - vs. Cincinnati Reds @ 12:30 p.m.

7/7 - vs. New York Yankees @ 7 p.m.

7/21 - vs. Boston Red Sox @ 12:30 p.m.

8/4 - vs. Kansas City Royals @ 12:20 p.m.

8/18 - vs. Toronto Blue Jays @ 12:30 p.m.

9/8 - vs. Seattle Mariners @ 7 p.m.

9/22 - vs. Chicago White Sox @ 12:30 p.m.

Open every day, San Francisco's Ferry Building Marketplace is a foodie mecca, offering fresh organic produce, gourmet treats, and fine dining. With a focus on small, regional food producers -- and many eateries and small businesses owned by well-known top chefs -- you can sample local artisan cheeses, chocolates, breads, and more.

Most Saturday mornings, celebrated Bay Area chefs stop in to demonstrate ways to prepare the sustainable, seasonable goods found in the Farmers' Market. Visitors can watch these experts in action, taste their creations, and leave with recipes to try themselves at home. Programs sometimes include interviews with farmers, food artisans, or other Farmers' Market vendors.

See the CUESA's website for a full event schedule.

Part of the annual summer-long Yerba Buena Gardens Festival, the Let's Go Dance@Jessie series is a downtown open-air dance party. It happens the first Thursday of every month May - October in Jessie Square (next to the Contemporary Jewish Museum).

Come early for a dance lesson -- the beginning of every program features lessons in a style of dance fitting the live music of the evening.

May 6: Orquestra la Moderna Tradicion (Cuban danzon)

June 3: A Klezmer Wedding Celebration with Kugelplex (Klezmer)

July 1: Lavay Smith & The Red Hot Skillet Lickers (Swing)

August 5: Tom Rigney & Flambeau (Cajun)

September 2: Edessa (Balkan)

October 7: Kumu Hula Shawna Alpa'i & Na Pua O Ka La'akea with Faith Ako (Hula)

On Wednesdays and Sundays, the Heart of the City Farmers Market sets up shop in the United Nations Plaza near City Hall, bringing locally grown produce, fresh flowers, and artisan goods to the city's Civic Center.

Go stock up on goodies to cook up back at the hostel, or snacks to bring along on your travels.

Join a park ranger any Saturday or Sunday for this free walking tour focused on the history of San Francisco's northern waterfront.

Sights include Aquatic Park Historic Landmark District, the Cannery, Hyde Street Pier, and Fish Alley in Fisherman's Wharf.

A beloved San Francisco tradition since 1938, the Stern Grove Festival presents free outdoor concerts every Sunday throughout the summer.

The festival's 73rd season runs from June 20 through August 22, at the Sigmund Stern Grove, a beautiful meadow surrounded by towering eucalyptus and redwood trees. Before each concert, from noon to 1 p.m., take your family to the KidStage, where different activities such as learning to dance, play drums, or make a mural are featured each week.

This summer, see:

June 20 - Angelique Kidjo and Sarazino

June 27 - HAPA and the Academy of Hawaiian Arts

July 4 - The San Francisco Opera, the San Francisco Opera Chorus & Orchestra: A Celebration of American Music featuring Patricia Racette and John Relyea

July 11 - The San Francisco Symphony, conducted by Donato Cabrera

July 18 - Caravan Palace and DePedro

July 25 - Jovanotti and Bomba Estereo

August 1 - Rickie Lee Jones and Meklit Hadero

August 8 - The San Francisco Ballet, directed by Helgi Tomasson

August 15 - Maceo Parker and Darondo

August 22 - They Might Be Giants and Rogue Wave

Once a month this summer, learn how to salsa (or shake it like a pro) to some of the Bay Area's best Latin music.

An introductory lesson starts off the evening in Union Square, followed by an open dance floor with live music.

Join us on Friday evenings for complimentary wine and nibbles at the San Francisco Downtown Hostel.

Meet and mingle with fellow travelers, whet your appetite for San Francisco’s nightlife, then hit the town together, or settle in to plan your next day's adventure.

This event is open to all guests at our three San Francisco hostels. No signup is required.

The Golden Gate Park Band has been playing free Sunday concerts in Golden Gate Park since 1882.

Their 2010 concert season (April 25 - September 26) runs the gamut from classical to circus music, opera to Americana, plus a wide range of ethnic music. The band collaborates regularly with various San Francisco ethnic and arts groups, who bring to the park their colorful costumes, dance groups, singers, and musicians.

Bring a blanket or lawn chair, pack a picnic, and enjoy one of America's oldest professional concert bands in the magnificent surroundings of Golden Gate Park.

Joining a handful of other weekly farmers markets in San Francisco, the Fort Mason Center Farmers Market opens June 6 and runs every Sunday through October.

The market will feature 50 local farm and prepared food stalls, including vendors selling fresh and/or organic produce, farmstead cheese, fish, meat, eggs, and fresh baked goods.

The market is a short walk from the Fisherman's Wharf Hostel.

Was it the housekeeper in the hostel kitchen with the candlestick???

Come join us for a competitive game of Clue / Cluedo, and dine on a delicious dish of the Southern classic, Jambalaya.

Popcorn and plenty of laughter can be expected. Plus, winners will get free all-you-can-eat pancakes the next morning!

This event is open only to guests of the San Francisco City Center Hostel. Please sign up in advance.

Meet up with your guide, Jesse, for a walk across the world-famous Golden Gate Bridge.

Learn fun facts, new trivia, and the history of one of California's most beloved icons while taking in the awe-inspiring views of the bay and the city beyond.

Once on the other side, the tour continues by bus into Marin County's picturesque Sausalito, and finishes with a scenic ferry ride back to San Francisco.

This event is open to all guests at our three San Francisco hostels. Please sign up in advance.

The City Center Hostel's TV room is transformed into "The Atherton Theater" each night for a themed movie night.

August themes are:

August 8-14: Vampire Films

August 15-21: Movies filmed or set in San Francisco

August 22-28: Gay Cinema Tribute

August 29 - September 4: The Wild West

This event is open only to guests of the San Francisco City Center Hostel. No signup is required.

Join us -- and your fellow hostellers -- for a pasta dinner at the Downtown Hostel.

Meet your dorm neighbors and plan your weekend in San Francisco over pasta (with meat sauce), salad, and garlic bread.

This event is open only to guests of the San Francisco Downtown Hostel. No signup is required.

Put on your drinking shoes, grab your ID (gotta be 21!), and join Jesse and Anthony for our weekly pub crawl.

Sip some brew (or a cosmo? tequila?) at three or four of the best bars near our San Francisco City Center and Downtown hostels, meet a bunch of other travelers, and enjoy a night out in SF!

This event is open to all guests at our three San Francisco hostels. No signup is required.

Every Friday, this roaming street food extravaganza spends the evening in Fort Mason.

Don't miss street tacos, burgers, curries, creme brulees -- you'll find anything that can be made and sold from a the back of a truck. There's also live music!

Participating vendors regularly include some of San Francisco's favorite food vendors, like Chairman Bao Bun Truck, Creme Brulee Cart, Curry Up Now, Gobba Gobba Hey, Hapa SF, and Kung Fu Tacos.

Movies are fun to watch on the big screen, and even better on a balmy night in the park.

Organized by the San Francisco Neighborhood Theater Foundation, Film Night in the Park is the Bay Area's premiere outdoor film series. From May to October, films are presented on a giant outdoor screen in beautiful park settings throughout the Bay Area, including three locations in San Francisco.

For five decades, the award-winning San Francisco Mime Troupe has presented socially relevant theater that enlightens, entertains, and provokes, with free outdoor performances of original productions that incorporate song, dance, music, and comedy.

This year, this Tony Award-winning company celebrates its 51st season with Posibilidad, or Death of the Worker.

San Francisco's Sunday Streets is modeled after the Columbian tradition of Ciclovia, which means "bike path" in Spanish. Every Sunday in that country, more than 70 miles of roads are closed to cars and 1.5 million runners, walkers, skaters, and cyclists hit the streets.

In 2008, San Francisco brought Ciclovia to the city, closing off selected roads on two Sundays. The events were a big success, drawing 30,000 people. This year, varying streets will be closed once a month through October.

May 23, it happens in Bayview -- 3rd Street will be closed to cars between China Basin and Bayview Playground. This event is followed by the Bayview Festival from 1 p.m. - 5 p.m. between Galvez Avenue and Mendell Plaza.

June 20 and July 11 it's in the Mission, centered at Valencia and 24th streets.

August 22, it runs between the Academy of Sciences in Golden Gate Park to the SF Zoo.

September 19, it's in the Western Addition near Alamo Square.

October 24, it's in Civic Center Plaza and the Tenderloin nearby.

See the website for more details on each.

No matter which Sunday Street you attend, expect plenty of fun activities. Some of the highlights from previous Sunday Streets include skate dance demos inspired by Slumdog Millionaire, bike rentals, live bands and street performers, yoga and tai chi, as well as kid-friendly activities like carnival games, slides, and a climbing wall. Sunday Streets are also just a great chance to explore San Francisco neighborhoods in a relaxed, car-free atmosphere.

The Picklewater Free Circus Festival -- which runs for three Sundays in September, is in Union Square for its 2nd year, bringing free circus to Bay Area families and guests.

The festival will feature a mix of professional and student performers and a variety of circus styles.

Penny pinchers with refined taste in theater will be delighted to learn about Free Shakespeare in the Park, where seasoned professionals offer Shakespeare to the masses during nine performances in San Francisco's historic Presidio.

This year's play is Two Gentlemen of Verona, directed by Kenneth Kelleher, known for his "arresting visual style and use of music and dance." Saturdays, the show is at 7:30 p.m.; Sundays it's at 2:30 p.m.

Free Shakespeare in the Park was the first program created by the San Francisco Shakespeare Festival, a nonprofit organization based in the city. Since debuting in 1983 in Golden Gate Park, the program has expanded to various Bay Area locations with performances over the course of two months every summer.

The backdrop of this year's San Francisco performances is the Presidio, one of the largest parks in San Francisco, and one of the very oldest, dating back to the Spanish missionaries of the 1700s. Park visitors will notice the historic cannons and old military buildings, along with beautiful views of the city and Golden Gate Bridge from nearby viewpoints.

Born in Scotland, bred across the States, the Fringe Festival invades downtown San Francisco, from the Financial District to the Mission, in a multi-ring circus of audacious theatrical performances.

Produced each September by the EXIT Theatre, the San Francisco Fringe Festival is open-access and not curated, which provides total creative freedom for artists and encourages them to take risks, explore ideas, pose questions and tell their stories in new and exciting ways.

This year's schedule is online here.

The 15th Annual Ghirardelli Square Chocolate Festival returns to the San Francisco waterfront!

Indulge in chocolate delicacies, sip at the wine and chocolate bar, and enjoy chef demonstrations and other family activities.

SFJAZZ Summerfest is an annual series of outdoor concerts, featuring over 30 events throughout the Bay Area. Summerfest showcases local musicians displaying a wide array of styles, including Latin, swing, blues, and more.

From September 8 through October 13, groove to the tunes in San Francisco's Levi's Plaza, amid rolling lawns, shade trees, and a running creek.

The schedule includes:

September 8: Nice Guy Trio

September 15: Brass Manazeri

September 22: Tin Cup Serenade

September 29: The Lost Trio

October 6: Peter Horvath

October 13: lisa Engelken

Visit the SFJAZZ website to see the full festival schedule.

Though still relatively new to the United States, Moon Festival celebrations have been held throughout Asia for well over 1,000 years, and San Francisco's Autumn Moon Festival has been Chinatown's best-attended annual event for several years running.

A significant holiday on the Chinese (lunar) calendar, the Moon Festival is a time to reflect upon the bounty of the summer harvest, the fullness of the moon, and the myth of the immortal moon goddess, Chang O, who lives in the moon. The Moon Festival is often compared to a sort of "Chinese Thanksgiving" because of its spirit of gratitude and its inclusion of abundant food, including the popular moon cake.

The weekend-long celebration features several stages throughout Chinatown showcasing a variety of live entertainment. Performers this year include a host of Asian-themed dancers and drummers, traditional and contemporary musicians, martial artists, and magicians. In addition, hourly lion dance performances will take place along Grant Avenue

Chinatown's many street vendors will offer visitors everything from plants to housewares, clothes to souvenirs. And, as always, the Moon Festival presents a variety of special offers, activities, arts and crafts, and food along the main festival route.

Friends of the San Francisco Public Library put on what may well be the biggest book sale on the West Coast, which is going 45 years strong.

The sale, occupying the vast Fort Mason Festival Pavilion, features more than 300,000 previously owned books available at remarkable savings ($5 or less each title).

There are more than 50 categories of books on sale, including rare books, first editions, and of course, many books that just can't be categorized. On Sunday, all books are $1 or less!

With its roots in Southern China dating back nearly 2,000 years, dragon boating has grown into a popular sport with a large international following.

The San Francisco International Dragon Boat Festival is one of the largest dragon boat festivals held in North America, with nearly 100 teams and 3,000 paddlers coming from across the continent to race on Treasure Island's 300- and 500-meter courses.

Watch as these boats -- each manned by 20 paddlers, a steer person, and a drummer to set the paddling rhythm -- race across the waters of the island's Clipper Cove, and cheer for your favorite team.

Aside from the exciting races, the festival also features live entertainment, craft vendors, and international food booths.

Free shuttle service between Treasure Island and San Francisco is provided both days of the event, running every 15-20 minutes between 9:30 a.m. and 4:30 p.m. Take your pick of two convenient drop-off/pick-up locations in downtown San Francisco, one in Chinatown (at the corner of Washington and Kearney streets), and one at the Marriot Hotel near the corner of 4th and Mission strees. See the festival's website for more detailed transit information.

Leave your inhibitions at the hostel if you're planning to take part in the Folsom Street Fair. The politicians roll up for photo-ops with a dominatrix, non-gays join in the leather-bondage parades, and the atmosphere is friendly and inclusive at the world's biggest leather event.

Every year about 400,000 leather folk of all types --  queer, straight, male, female, trans -- turn out for a grand finale celebration of kinky love at the end of Leather Pride Week. Vendors from all over the country come to flog their wares to a sex-positive crowd: everything goes as long as it's consensual.

The street fair also hosts two live stages with 16 live alternative acts, a huge dance area with internationally renowned DJs, and a newly inaugurated artists' area. Musical performers in past years have included Berlin, Shiny Toy Guns, The Presets, The English Beat, and many more.

Everyone, gay or not, is proud of San Francisco's acceptance and the Folsom Fair celebrates just that. Even so, the bare flesh, the leather, and the muscled torsos are quite mind-blowing, and if you do take a camera, you won't know what to snap next as you find yourself surrounded by some of the most outrageous leather, rubber, and fetish attire.

Through state-of-the-art technology, a live performance of the San Francisco Opera's Aida will be simulcast (in high definition, no less) to AT&T Park's 103-foot wide "Diamond Vision" scoreboard -- the highest quality outdoor scoreboard in the nation -- from the stage of San Francisco's War Memorial Opera House.

Baseball fans and opera fans alike have a chance to experience this free event with seating both on the field and in the stands.

Guests are encouraged to bring a picnic dinner, or they can opt for the more traditional baseball game concessions that are available for sale throughout the park.

Advanced online registration is free, and allows guests early entrance into the ballpark for the best seating. Also, registered guests are entered in a prize drawing for a "grand night at the opera" package.

The Fisherman's Wharf Hostel shows movies at 8 p.m. nightly, Tuesday-Sunday, in themes that vary week to week.

Popcorn is always free, and on Fridays and Saturdays, the hostel's Cafe Franco offers discounted, homemade pizza for $2.50 a slice.

Meet up with your new hostel friends in our theater style TV lounge downstairs, and chill out to the evening flick.

Labor Day signals the end of most Americans' summer vacations -- but you're still on yours, so enjoy it!!

Meet and mingle with other hostel guests from around the world as you munch on grilled hot dogs, hamburgers, veggie burgers, and other tasty BBQ treats. Sunbathe on the hostel's grassy front lawn, enjoy some groovy tunes, and make new friends over the indoor pool table while waiting for the next round of franks.

After you've eaten your fill, meander down the wooded path behind the hostel to take in the stunning sights of the Golden Gate Bridge, Alcatraz, and the shining bay.

This event is open to all guests at our three San Francisco hostels. No signup is required.

San Francisco is best on two wheels, so join your guide Larry for a fun and scenic bicycling tour along the Bay. Cruise through historic Fort Mason and serene Crissy Field. Stop at the Palace of Fine Arts then bike across the world famous Golden Gate Bridge.

The first stop will be Blazing Saddles Bike Rental, where your wheels for the day will cost $18 (includes helmet, lock, rear rack, camera bag, bungie cord, and a map).

This event is open to all guests at our three San Francisco hostels. Please sign up in advance.

Looking to relax, recaffeinate, chill out with your new hostel buddies, or just think tea is awesomely satisfying???

Stop by Ivy's Place, our Prohibition-era cafe parlor for a free Chinese loose leaf tea tasting.

This event is open only to guests of the San Francisco City Center Hostel. No signup is required.

Tuesday nights, the hostel's TV room is transformed into the Atherton Theater -- join other hostellers to hang out and enjoy a film.

Films vary each week, from cult classics to San Francisco flicks to current blockbusters.

This event is open only to guests of the San Francisco City Center Hostel. No signup is required.

Come with us into Chinatown for the annual Autumn Moon Festival.

Hostellers will have the chance to catch live music, traditional dancing, delicous Chinese food, and more during the beautiful celebration in one of San Francisco's most enjoyed neighborhoods.

For more information on the event, see our separate calendar listing.

This event is open only to guests at any of our three San Francisco hostels. Please sign up in advance.

Comedy Day is a free, outdoor stand-up comedy concert featuring nearly 30 of today's top performers, held in San Francisco's Golden Gate Park.

Since its founding in 1981, more than 500 of the world's funniest comedians have performed free-of-charge for over a half-million people at Comedy Day.

A list of this year's performers can be found here.