Fiery Furnace
Fiery Furnace in Arches National Park is a great way to spend an entire day. The area itself isn't that big, but it is a maze of small slot canyons, fins, washes, boulders and walls that you can play around in for hours. Almost every formation makes you wonder "How can I get up on top of that?" or "I wonder what's at the other end?" You need a permit for entry, the price of which is $4 and 5 minutes of your life watching a Leave-No-Trace video, which actually wasn't too bad.
If you don't have time to explore, the Ranger guided tour is probably the way to go, since they will show you the highlights in just a couple of hours. But if you like exploring, get the permit and check it out yourself.
We hiked Fiery Furnace (which by the way is not named for the heat, it is fairly cool in most parts due to the shade from the formations) with our kids in backpacks. That limited the amount of scrambling we could do, but we still had a great time checking out the closer canyons and formations. Daddy only got carried away one time; you can click on the injury pic at the bottom for the whole story.
Cryptobiotic Soil - Don't tread on me
You get a nice view of the mountains from Fiery Furnace
