San Francisco is on a peninsula surrounded by the Pacific Ocean, the Golden Gate strait, and San Francisco Bay. It's hilly in places in flat in others. The underlying rock is mostly the Franciscan melange but there is also sandstone.
The San Andreas fault is offshore to the west of the Peninsula, entering the water in Pacifica right around Mussel Rock.
The west side of the peninsula used to be mostly sand dunes, and the east side much more marshy.
Several islands fall within the city's boundaries, including Treasure Island, Angel Island, Alcatraz Island, Yerba Buena Island, the Farallon Islands, and some of Alameda Island, Angel Island, and Red Rock Island.
Notable features
The seven original hills:
Telegraph Hill, Nob Hill, Russian Hill, Rincon Hill, Mount Sutro, Twin Peaks and Mount Davidson
Other hills include:
Bernal Hill Buena Vista Heights Parnassus Heights Potrero Hill Strawberry Hill
Water:
See also:
