I think you’re thinking of the complex on Mauna Kea (which has several individual sites and has funding from several countries).

Mauna Loa has a telescope that studies the Sun in order to help understand better how that contributes to changing weather patterns on Earth. It is a relatively small site but very important.

The reason that telescopes are often in high up, hard to reach places is because that is the most efficient, cost-effective place for them to be.