The Gran Telescopio Canarias (meaning "Canaries Great Telescope"), also known as GranTeCan or GTC, is a 10.4 m (410 in) reflecting telescope undertaking commissioning observations at the Roque de los Muchachos Observatory on the island of La Palma, in the Canary Islands of Spain, as of July 2009.
Construction of the telescope, sited on a volcanic peak 2,267 metres (7,438 ft) above sea level, took seven years and cost €130 million (£112 million). Its installation had been hampered by weather conditions and the logistical difficulties of transporting equipment to such a remote location. The GTC Project is a partnership formed by several institutions from Spain and Mexico, the University of Florida, the National Autonomous University of Mexico, and the Instituto de Astrofísica de Canarias (IAC). Planning for the construction of the telescope, which started in 1987, involved more than 1,000 people from 100 companies. As of 2009, it is the world's largest single-aperture optical telescope. The distribution of the availability of time to use the telescope meets its financial structure: 90% Spain, 5% Mexico and 5% the University of Florida.