Hawaii:
Mauna Kea Observatories http://www.ifa.hawaii.edu/mko/
Hawaii is Earth's connecting point to the rest of the Universe. The summit of Mauna Kea on the Island of Hawaii hosts the world's largest astronomical observatory, with telescopes operated by astronomers from eleven countries. The combined light-gathering power of the telescopes on Mauna Kea is fifteen times greater than that of the Palomar telescope in California -- for many years the world's largest -- and sixty times greater than that of the Hubble Space Telescope.
The highest point in the Pacific Basin, and the highest island-mountain in the world, Mauna Kea rises 9,750 meters (32,000 ft) from the ocean floor to an altitude of 4,205 meters (13,796 ft) above sea level, which places its summit above 40 percent of the Earth's atmosphere.
Mauna Kea Telescopes Optical/Infrared
UH 0.6m UH 0.6-m telescope 0.6m University of Hawaii 1968
UH 2.2m UH 2.2-m telescope 2.2m University of Hawaii 1970
IRTF NASA Infrared Telescope Facility 3.0m NASA 1979
CFHT Canada-France-Hawaii Telescope 3.6m Canada/France/UH 1979
UKIRT United Kingdom Infrared Telescope 3.8m United Kingdom 1979
Keck I W. M. Keck Observatory 10m Caltech/University of California 1992
Keck II W. M. Keck Observatory 10m Caltech/University of California 1996
Subaru Subaru Telescope 8.3m Japan 1999
Gemini Gemini Northern Telescope 8.1m USA/UK/ Canada/Argentina/Australia/Brazil/Chile 1999
Submillimeter
CSO Caltech Submillimeter Observatory 10.4m Caltech/NSF 1987
JCMT James Clerk Maxwell Telescope 15m UK/Canada/Netherlands 1987
SMA Submillimeter Array 8x6m Smithsonian Astrophysical Observatory/Taiwan 2002
Radio
VLBA Very Long Baseline Array 25m NRAO/AUI/NSF 1992