An observatory owned and operated by the Instituto de Astrofísica de Canarias (IAC) at an altitude of 2396 m on La Palma, Canary Islands, founded in 1979. Telescopes belonging to various nations are sited here. The largest is the 10.4-m Gran Telescopio Canarias (GTC), opened in 2009. Next-largest is the 4.2-m William Herschel Telescope, part of the Isaac Newton Group that also includes the Isaac Newton Telescope and the Jacobus Kapteyn Telescope. Other major telescopes at ORM are the Telescopio Nazionale Galileo; the Nordic Optical Telescope; the Liverpool Telescope; the 1.2-m Belgian Mercator Telescope, opened 2001; the 0.97-m Swedish Solar Telescope (SST), a vacuum tower telescope, opened 2002; the 0.45-m Dutch Open Telescope (DOT), a solar telescope opened in 1997; and SuperWASP-North, an array of eight wide-angle cameras of 0.1 m aperture for detecting transits of stars by extrasolar planets, which began operation in 2004. ORM also contains two gamma-ray detectors of the Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) Consortium.

http://www.iac.es/eno.php?op1=2&lang=en Official observatory website.