One of my favourite hikes from Southern Utah was definitely the slot canyons of Escalante National Monument.  We explored the parallel canyons, Peek-a-boo, & Spooky Gulch, which are about  45 minutes down a washboard road from the town of Escalante.  After a mile or so hike in form the trailhead, you find the inconspicuous entrance to Peek-a-boo, where, with a little scrambling you can climb up into an otherworldly hike.  There are some real challenges, it gets very narrow, and you need some serious agility to be able to complete both hikes.  Certainly not for the claustrophobic.  I'd recommend this experience to anyone heading to this part of Utah, as it is a hike you will not soon forget!