Walnut Canyon was a drive-by opportunity that we spotted, as we were getting close to our destination in Flagstaff AZ. Turns out that access to the National Monuments is also included in our lifetime National Parks pass!
Walnut Canyon is very popular, judging by the nearly overflowing parking lot, and it is indeed a wonderful hike, with a lot of vertical drop, which give us our first chance to see ancient cliff dwellings
After lunch, we visited the Museum or Northern Arizona, which was very interesting, and learned more about the native inhabitants of the area, as well as their artifacts and art.