Mauna Kea observatories. Dawn view of some of the astronomical observatories on Mauna Kea in Hawaii, USA, with a full moon in the sky. From lower left the observatories are: Subaru (Japanese telescope); Keck I & II (twin domes); NASA Infrared Telescope Facility. The remoteness of the Hawaiian islands from major landmasses and industry means that the air is free of dust and pollutants, making it one of the best observatory sites in the world. The observatories are sited at an altitude of 4200 metres near the summit of the dormant volcano Mauna Kea.