Don't miss the sensation of moving up and down some of San Francisco's steepest hills in a clattering cable car, the only moving thing listed on the National Register of Historic Places. As it pauses at a designated stop, jump aboard and wedge yourself into any available space. Then just hold on.
The fare (for one direction) is $5 (Muni Passport holders pay a $1 supplement). You can buy tickets on board (exact change isn't necessary) or at the kiosks at the cable-car turnarounds at Hyde and Beach streets and at Powell and Market streets.
The heavily traveled Powell-Mason and Powell-Hyde lines begin at Powell and Market streets near Union Square and terminate at Fisherman's Wharf; lines for these routes can be long, especially in summer. The California Street line runs east and west from Market and California streets to Van Ness Avenue; there is often no wait to board this route.