Best activities for kids

Don't know the ages of your boys---SF Giants baseball game and/or tour of AT& T ball park. The Exploratorium at The Embarcadero. Walking around Fisherman's Wharf and http://www.madametussauds.com/SanFrancisco/ and Ghiradelli Square for ice cream. The National Academy of Sciences in Golden Gate Park, also the Japanese Tea Garden. San Francisco Chinatown is fun, too. There are many more activities such as renting bikes and riding across the Golden Gate Bridge, etc. Have fun!

Definitely the Exploratorium. Great exhibits and lots of hands on things that they boys can play with and not have to worry about trying not to break things.

Some great parks - Try the Presidio Heights Playground - super fun and very friendly area.

Walk The Embarcadero starting at about Folsom street and walk towards the Ferry Building. A great culinary adventure awaits a good walk.

Bay Area Discovery Museum - just across the Golden Gate Bridge. Super fun for kids of all ages.

Golden Gate Park - specifically the carousel and slides park.

All of the above suggestions have some awesome spot for rambunctious young ones. I also want to suggest the  San Francisco Zoo. They always house a unique variety of animals that your boys aren't neccessarily bound to see at any other zoo- I still remember that I saw my first and only white alligator there when I was a kid. That stuck with me!

Your boys may also get a lot of entertainment from riding the  Cable Cars. Not only is this a must-do if you're a visitor of any age in San Francisco, but it also gives young kids the chance to feel like they're on a 'ride'. This can take you anywhere in San Francisco, too, so you can choose where to get off.

Lombard Street, the most winding road in the U.S., is zany and on a huge slope, so this provides another easy-entertainment option to see with your kids.

North Beach (California), San Francisco's Little Italy, is known amongst the locals as an extremely kid-friendly place to dine. The food is almost all Italian, so your kids are bound to delight in mounds of spaghetti or authentic pizza. This is a great place to eat for the more mature crowd as well, as you'll appreciate the authenticity of the Italian flavors. I recommend  Tony’s Pizza Napoletana, whose owner is none other than the 11-time World Pizza Champion, Tony Gemignani. This joint, which imports all of its ingredients from the world's pizza capital- Napoli- serves up their artisinal pizzas in a variety of crusts to choose from. Diners have the choice of all kinds of thin or thick crusts, ranging from the typical, Brooklyn-originated styles to the more traditional, real-Italian styles.

Depends on the age, but Google these:

Exploratorium

California Academy of Sciences

Koret Children’s Quarter ( Golden Gate Park)

Yerba Buena Gardens (Downtown)

You might also think about some day trips outside the city.  Sausalito is close to some great hiking and trails (eg Mount Tamalpais).  There's a very good fish restaurant (Fish.) on the water with picnic benches outside.  We like to go for a hike then have picnic lunch afterward.

Definitely check out the Exploratorium on the Embarcadero.  It's a great place to check out with kids.  So is the California Academy of Sciences if they're into fish and reptiles.  Pier 39 has the aquarium, but I think it's overrated. 

Alcatraz?  What kids wouldn't like prison tours? 

Exploratorium on Embarcadero and the Planetarium by Golden gate park

Definitely take them to the Exploratorium. It is a fun science museum with tons of hands on fun for kids. You can also walk along The Embarcadero to Fisherman's Wharf, which is very touristy, but fun for kids. Alcatraz has night tours that are awesome. Google it and book tickets online ahead of time though. They sell out.  

Have a great time in our beautiful city. 

the best place is the Golden Gate Park, they can run play, skate, ride in their bikes or visit any of the great museums: the De Young Museum (art) and specially the California Academy of Sciences. there is a Japanese Tea Garden, and the San Francisco Botanical Garden .

A bike ride across the Golden Gate Bridge! Most people rent a bike from a place near Fisherman's Wharf and bike over to Sausalito to have lunch and walk around in the afternoon. There is a ferry that takes you back to San Francisco.

Further up north is Muir Woods, which has nice hiking trails and large redwoods.

Hope y'all enjoy SF!

Check out the cable cars!  You can get on at Union Square.  It's $6 per person, but it's a great way to check out the city.  Also, kids love standing and hanging off the side of the car!  

Depending on the boys' ages the Exploratorium and California Academy of Sciences are both good places to go with them.  

There is also a good rock gym and trampoline place (House of Air) next door to each other at Crissy Field that could be fun if they are older.

Renting bikes and riding over the bridge to Sausalito and taking the ferry back is a good excursion that should get them nice and tired out while providing a great view of the city.

San Francisco Zoo is very nice, also Fort Funston has great trails & hang gliders.

You should go to the Aquarium of the Bay, Pier 39 and Fisherman's Wharf.
Next day, you should rent a bike and ride through the Presidio and then go to visit the Golden Gate Bridge.

Depending on how old they are, the San Francisco Zoo is a good place for children under 8 as the new playground is excellent for active children. The Discovery Museum is good for younger children. Also, the Exploratorium is a neat place for children to explore. Good luck & have fun!

My favorite place that I ever went as a kid (very active) was the Exploratorium. Its a VERY interactive science museum, and it is AWESOME. I would dream about visiting that place again as a child. hope this helps!

Golden Gate Park is huge & full of adventures (rent bikes, ride horses, paddle boats, beach, etc)

How old are they? What dates? There are lots of playgrounds, House of Air, Circus Center, paddle boats in Golden Gate Park, Church of 8 Wheels (disclaimer: I'm involved in that one), ...

Golden Gate Park is full of activities. Try the California Academy of Sciences. Or the brand new Exploratorium on The Embarcadero.