Saturday, 10 a.m.
You might have heard that San Francisco has hidden staircases, but did you know that there are hidden slides? Grab a piece of cardboard big enough to sit on and head to the park on the corner of Seward and Douglass, in the Castro District, where you'll find the sky-high chutes built into the side of a hill. There are stairs to take you to the top. If you don't happen to have a pizza box handy, no problem. You'll likely find some cast-off cardboard (or maybe even a fast-food tray, which makes you go faster) on-site. Spend a morning sharing good cheap (free, actually) thrills and an adrenaline rush with local families.