A number of important astronomical observatories are located in the Hawaiian Islands, including what is probably the best ground-based telescope site in the world: the summit of the extinct volcano Mauna Kea on the Big Island of Hawaii. Some important telescopes there include the National Astronomical Observatory of Japan’s Subaru Telescope, the Gemini North Telescope, the James Clerk Maxwell Telescope, the Sub-Millimeter Array, the NASA Infrared Telescope Facility, the Canada-France-Hawaii Telescope, and the twin Keck Telescopes.