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.
While one can hike to the bottom of Sipapu Bridge, the Kachina bridge can only be seen from a distance. And that too after a hike. If you are short on time, skip this one.
Owachomo Bridge, the last one, also requires a hike down to the bottom. The hike is more comfortable than the hike to Sipapu bridge, though. There is a strenuous climb to the top of the bridge on the right.