Hetch Hetchy aqueduct bay crossing

The historic Hetch Hetchy Aqueduct, a pipeline from a reservoir in the Sierras that carries much of San Francisco's water supply, plunges into the Bay briefly next to the old Dumbarton Cut-off railroad bridge. It emerges in an octagonal structure on the end of a pier, and continues towards the city, flowing through the Pulgas Water Temple before spilling into the six-mile long Crystal Springs Reservoir, above San Carlos.