What are some great outings for a Webelos II den in the SF Bay Area?

Answer 1

The Exploratorium. (FREE first Wednesday of the month, but groups of ten or more MUST make reservations or won't be admitted)

Coyote Point Museum (FREE on the first Wednesday of each month)

California Academy of Sciences in Golden Gate Park, also free on the first Wednesday.

Answer 2

Try the Lawrence Hall of Science, Chabot Space and Science Museum, see if arts and crafts shops will host an art event, see if you can find someone to work with the boys to build a catapult or bridge for their engineering badge, take them camping, USS Hornet, earn their Aquanaut badge at a local pool, take them to a play, ....