twin telescopes of Keck Observatory in Hawaii

The observatory sits close to the summit of the dormant volcano Mauna Kea, at an altitude of 4,205 metres (13,796 feet). Each of the two telescopes has a primary mirror formed by 36 hexagonal segments, with an overall diameter of 10 meters (32 ft 10 in). Completed in 1993, Keck Observatory is one of the leading observing facilities in the world for astronomical research in visible and infrared light.