Thought we'd be walking along a flat desert floor with an occasional boulder to clamber over...
Wow, were we surprised! First, each person was given a small technical backpack, 4+ bottles of water, and snacks. Then, we started out on what would be nearly 4 hours of: walking along sandy paths, but also hiking more rugged terrain; descending into corridors of towering, 10+ story rock formations on either side; climbing up onto those rock formations to breath-taking views of the entire Valley; crawling into caves - and out again!; scaling rock faces; learning some pretty awesome history - natural, historical and pop culture for the area!
We are merely novices, having done some rather basic to intermediate hiking with our sons' Boy Scout Troop over the years. And this hike was perfect for our skill level. It was comfortable, but it was also challenging to what we would consider our limits. Although we were tired by the time we returned to the parking lot, we would NOT have changed anything about the hike.