On the way to Ajo for the Fiddler's Convention, we stopped in Tucson overnight so I could go to Kitt Peak.
They were offering solar viewing the day we were there. They have the largest solar observatory in the world. This is only the part above ground. There is almost twice that distance below ground.
This is where the solar light beams enter using a 2 meter flat mirror.
The beam is directed 135 meters below to a 1.6 meter concave mirror.
The beam is returned to this 1.5 flat mirror where it is beamed down to an observing room below. To keep distortion to a minimum, they keep the interior of the observatory the same temperature as outside.