The Valens Aqueduct is the most prominent Roman ruin in Istanbul. This ancient 800m-long landmark, which runs between the third and fourth hills 20m above the Atatürk Boulevard, has been dominating the urban landscape for more than 16 centuries. Completed around 378, it supplied the imperial palace with water. Damaged by several earthquakes and reconstructed each time, a significant part of it was removed in 1912, during redevelopment of the area around the Fatih Mosque.