The Large Binocular Telescope (LBT) is an optical telescope for astronomy located on 10,700-foot (3,300 m) Mount Graham, in the Pinaleno Mountains of southeastern Arizona, United States. It is a part of the Mount Graham International Observatory. The LBT is currently one of the world's most advanced optical telescopes; using two 8.4 m (330 inch) wide mirrors, with centres 14.4 m apart, it has the same light-gathering ability as an 11.8 m (464 inch) wide single circular telescope and detail of a 22.8 m (897 inch) wide one. Its binary nature make ranking it as superlative somewhat more confusing, overall one of the largest telescopes in the world and in some measure the largest.