Every Sunday JFK Drive, Golden Gate Park’s main thoroughfare, is closed to cars. Out come the bikers, strollers, skaters, runners, and dancers. Enjoy the park’s quieter, calmer side but be sure to check out the roller-disco enthusiasts at 6th Ave. from 1-5, and the lindy dancers (including free lessons) in front of the DeYoung Museum from 11-2. Golden Gate Park; goldengatepark.com.