Hawaii

And the opposition to this project is bollocks.

The TMT is to be built on the existing observatory grounds which were set aside for this very use decades ago.

Note the altitude there, 4,205 meters (about 13,800 feet). Of course, workers there have to be acclimated to the 40% of sea level atmospheric pressure there. And of course, oxygen is available on site for those who get faint. It is an environment useful for little else but world class astronomy which is why the observatory is located there in the first place. And note that no other site in the northern hemisphere comes close to the Mauna Kea summit for visual astronomy. None!

To build the TMT anywhere else would be negligent. Mauna Kea is where this telescope belongs.

Regards