Roque de los Muchachos Observatory (Spanish: Observatorio del Roque de los Muchachos, ORM) is an astronomical observatory located in the municipality of GarafĂa on the island of La Palma in the Canary Islands, Spain. The observatory site is operated by the Instituto de AstrofĂsica de Canarias, based on nearby Tenerife. ORM is part of the European Northern Observatory.
The seeing statistics at ORM make it the second-best location for optical and infrared astronomy in the Northern Hemisphere, after Mauna Kea Observatory, Hawaii. The site also has some of the most extensive astronomical facilities in the Northern Hemisphere; its fleet of telescopes includes the 10.4 m Gran Telescopio Canarias, the world's largest single-aperture optical telescope as of July 2009, the William Herschel Telescope (second largest in Europe), and the adaptive optics corrected Swedish 1-m Solar Telescope.