A complex of observatories and telescopes at an altitude of approximately 4200 m on the summit of Mauna Kea island, Hawaii. The site, founded in 1964, is owned and managed by the University of Hawaii’s Institute for Astronomy. It is the world’s highest observatory site and is generally regarded by astronomers as the best location for ground-based optical, infrared, and millimetre/submillimetre observations. More major telescopes are located on Mauna Kea than at any other site. The University of Hawaii has its own 2.2-m and 0.9-m reflectors on Mauna Kea, opened in 1970 and 2010 respectively (the 0.9-m replaced a 0.6-m opened in 1968). Optical and infrared telescopes from other organizations are the NASA Infrared Telescope Facility; the Canada–France–Hawaii Telescope; the United Kingdom Infrared Telescope; the Gemini North telescope (see Gemini Observatory); the Japanese Subaru Telescope; and the W. M. Keck Observatory. Radio and millimetre-wave instruments on Mauna Kea include the James Clerk Maxwell Telescope; the Smithsonian Astrophysical Observatory’s Submillimeter Array; and a 25-m antenna of the Very Long Baseline Array.

http://www.ifa.hawaii.edu/mko/ Official observatory website.