There are several astronomical observatories on Mauna Kea.

An excerpt from the article 16 facts about Hawaii

There are 13 telescopes installed on the volcano for observations in various ranges of electromagnetic waves: visible, infrared, radio, and sub-millimeter (deep infrared). This place was chosen because it is one of the few locations on Earth with excellent conditions for observing space. Because Hawaii is located in the middle of the ocean, the sky is very dark, constant temperatures guarantee low air turbulence, and the high location ensures the absence of clouds that are lower than the telescopes.