The California Academy of Sciences is an amazing museum, and once in awhile it's FREE! Come visit this world-class scientific & cultural institution located in Golden Gate Park. This fun, interactive, and super interesting museum has an aquarium along with a natural history museum, a planetarium and even a four-story rainforest. Early arrival for admission to the Academy of Sciences is always recommended due to the extreme popularity and high demand on free day. Final entrance time is 5pm, so don’t be late! If you can't come this time, be sure to check out the Academy of Sciences every Thursday night when they do $15 admission from 6-10pm along with bars, music, and special performances and presentations (21 and up only!)