Kitt Peak used to be the premier US observatory. Even though there are much larger telescopes and sites now, yet it remains an impressive place.
This is my third trip to Kitt Peak, but my first chance to observe on the Mayall 4-meter telescope. The first thing to know about the 4-meter is that it is a colossal maze. Literally. There are 16 stories of rooms, now obsolete and out of date, before reaching the base of the telescope itself.