Lined with exhibits designed by MacArthur Genius Grant winners, the Exploratorium bills itself as "a museum of science, art, and human perception." This is a hands-on, interactive experience, so bring the kids and get ready to play with everything from dissected cow eyes to your own shadow. Tickets are $25. Open Tue and Thurs-Sun 10 a.m. - 5 p.m. Wed 10 a.m - 10 p.m.