Sunset observatory Mauna Kea
The world's largest telescope dedicated solely to infrared astronomy, UKIRT is sited in Hawaii near the summit of Mauna Kea at an altitude of 4194m above sea level. It is owned by the United Kingdom Science and Technology Facilities Council and operated, along with the James Clerk Maxwell Telescope (JCMT), by the staff of the Joint Astronomy Centre, which is located in Hilo.
Very exciting being up on the mountain at sunset. Luckily we weren't affected by altitude sickness, and it was a clear night.
Looked through the Visitor Centre telescopes at Northern hemisphere stars - everything upside down!