Natural Bridges National Monument in Utah is a National Park consisting of three natural bridges. One can spend ~1-3 hours hiking nearby each of the bridges. The hikes are short and require ascent/descent. Even without the hike, one can drive around to see the views.
Antelope Canyon is probably the most photographed canyon in the world. Located in the Navajo Indian preservation, only guided tours are permitted. We took a trip to Antelope Canyon Tours. The tour lasts about an hour, and it takes ~20 mins one-way drive to reach the canyon. There aren’t any hikes, just simple walks in the canyon. Everyone is crazy running around and taking photos, so it does become a bit hard to enjoy in the mad rush. Even then, if you are in the area, I would recommend booking a tour in advance to visit the canyon. ]