Cobb Peak (7,021 ft) was not my favorite hike or peak I've done. Let's just get that out of the way off the bat. This peak does not have a trail, very little shade, no water, has lots of bush whacking, and is very steep. Now, I've done my fair share of peaks with those qualities, but this one in the Silver Island Mountains seemed to kick my butt worse than the others.
Kanarra Falls is a great Utah waterfall hike. You get to hike in a very accessible and beautiful slot canyon, a chance to walk in the river on a hot day, and see several beautiful waterfalls. The biggest downside to this hike is the crowds - it has become a big issue in the past year or so (read about the issues going on here). Kanarra Falls is the perfect stop for amateur photographers looking for professional photo opportunities. This is also a great family hike - it requires only a 2-3 hours, no equipment or gear is needed, nor a high level of hiking skill. Even the kids will love this hike! You'll want to be sure to wear sturdy, water shoes as most of this hike is in the river.
Kayenta Canyon Trail is known by two names: Kayenta Canyon, and to the locals, Hellhole Canyon. This trail starts in the town of Ivins, UT, about 15 minutes west of St. George, UT. If you don't like walking in sand washes, this is not the trail for you. 90% of this trail is walking in the wash, and on a sunny day (most days in Southern Utah), it can get very hot. There is no water, no shade, and no restrooms.