There are many such ruins in the 4 Corners area. They were inhabited by the Anasazi for about 800-900 years until they abruptly picked up stakes and moved toward the south. The reason for that is unclear but most archeologists feel that it was due to a sustained drought.
There were a few nooks and crannies that it was fun to poke around it...Here's Judy thinking about doing some climbing
And I got a little wedged under a boulder and was about to go all "127 Hours" when Judy reminded me that I could easily just pull my arm free.