One of the more unusual things one finds in the East Bay of San Fran is this structure, the Sunol Water Temple. From the temple the water once flowed to the Niles Aqueduct in Niles Canyon and across San Francisco bay to San Francisco.

Prior to the construction of the Hetch Tetchy Aqueduct in 1914-34, half of San Francisco's water supply (6 million gallons a day) passed through the Sunol temple. While water still flows through the temple even today, it's not used with the potable water supply. It is one of two in the Bay Area, the other being the Pulgas Water Temple