Mauna Kea, Hawaii
Cinder cones north of the summit of dormant Mauna Kea Volcano in Hawaii. More and more of the summit cones have become perches for the largest and best telescopes on Earth. It's high -- 4206 meters; it's dry -- less than 300 millimeters of precipitation (mostly snow) per year; and it's away from much of the light and air pollution of continental locations.
U.S. Geological Survey photo by R.W. Decker.