Perched on the cliffs above Ocean Beach, the Cliff House has been a San Francisco landmark since the 1860s (though the current building dates from 1909). The site overlooks Seal Rocks, where sea lions bask and bark, and on clear days the views up and down the coast are spectacular.
The adjacent Sutro Baths ruins -- the remains of a massive Victorian-era swimming complex -- are worth exploring on foot. Trails wind down the cliffside to the ruins and along the coastal bluffs toward Land's End.