Hard to imagine from these ruins, but Victorian dandies and working stiffs converged here for bracing baths and workouts in itchy wool rental swimsuits. Mining magnate Adolph Sutro built hot and cold indoor pools to accommodate 10,000 unwashed masses in 1896, but the masses apparently preferred dirt, and the place was finally closed in 1952. Head through the sea-cave archway at low tide for end-of-the-world views of Marin Headlands.