San Francisco

San Francisco occupies the tip of a hilly peninsula between the Pacific Ocean and San Francisco Bay, guarding the Golden Gate — the narrow strait that is the only sea-level break in the California Coast Ranges and the gateway to one of the world's great natural harbors. That strategic position turned a small mission settlement into a boomtown overnight with the 1849 Gold Rush, and into the financial and cultural capital of the West Coast.

The city is famous for its hills — more than 40 of them — and for the fog that pours through the Golden Gate on summer afternoons, products of the cool ocean meeting the warm interior. Built directly across the San Andreas fault zone, it was nearly destroyed by the 1906 earthquake and fire and rebuilt. Water surrounds it on three sides, constraining the dense, compact city onto its peninsula.

Packed onto roughly 47 hilly square miles, San Francisco is among the most densely populated major cities in the country and the urban anchor of the Bay Area and Silicon Valley to its south. The bay, the Golden Gate, and the hills make it one of the most distinctive city sites in America.