Devil's Tower is located in the northeast corner of Wyoming near another great climbing area, the Needles (Mt. Rushmore is a Needle.)
It is an isolated volcano throat in a prairie. It is seven or eight hundred feet tall, though most of the climbs are much shorter, since on most sides you scramble up several hundred feet before starting a climb, and there is a lot of rubble that you climb unroped near the summit (often one just raps from where the rubble starts.) It features innumerable cracks between each column and lots of face climbing too on solid rock that looks a bit like fine grained granite (phonolit porphry.) This was the first National Monument.
Susanka's Front Door