Haleakala Observatory

Haleakala is known for the surreal sunrise bike rides down  its mountainside and the striking rainbows that scatter about the sky, but  Haleakala is also home to a complex known as "Haleakala Observatory," where  scientists come from all over the world to see what lies beyond Earth. Because Haleakala is above one-third of the  earth’s atmosphere at 10,000 feet and since Maui is part of the Hawaiian  Islands and therefore surrounded by water for many miles, there is very limited  light pollution. These reasons among  others make Haleakala Observatory a sought after home for ground based  telescopes. 

To read about the  different telescopes at Haleakala Observatory, check out these links:

http://ludb.clui.org/ex/i/HI3130/
http://www.ifa.hawaii.edu/haleakalanew/observatories.shtml