Three blocks uphill from Castro Street, two steep concrete slides run down the rock face of Seward Mini Park. They exist because the neighborhood fought for them: in the late 1960s residents blocked an apartment development on this slope, and the city held a design contest for the resulting pocket park. The winning entry came from Kim Clark, a 14-year-old who sketched the double slides in 1973.
Riders sit on flattened cardboard (regulars leave pieces by the top) and move fast; this is a real slide, not a playground ramp. The park is open daytime hours, closed Mondays, and posted rules ask that adults be accompanied by a child, which tells you who the city thinks the slides are for. The climb up Seward Street passes some of the prettiest hillside gardens in the neighborhood either way.