Moab is a unique Western community situated in the red rock country of Southeastern Utah on the Colorado River. Arches National Park is only six miles from downtown and Canyonlands National Park is 32 miles from Moab. The city is surrounded by public lands which are used not only for grazing, drilling, and forestry but for recreation such as mountain biking, hiking, rafting, rock climbing, and cross-country skiing. Because the area is rich in these recreational opportunities, Moab has become the hub of tourist activity and services.
If you are approaching Moab while driving west along I-70, it is highly recommended you use Utah route 128. About 10 minutes past the Colorado-Utah border is exit 214 on I-70, it is marked as "Cisco". The landscape at this point is extremely dry, slightly hilly. The road is narrow (no shoulder), and somewhat curvy, and it's about 80km to Moab. About half-way, the road narrows, meets then crosses the Colorado River, and the remainder of the trip is spent with the river on your right side and spectacular canyon walls surrounding you. This piece of pavement is, in the opinion of this writer, one of the best drives in North America. Optimal times to take it are the morning (~9am) or afternoon (after 3) for the light -- do not drive it at night (you can't see anything and more dangerous -- use US 191 instead). Watch for traffic, particularly bicycles as you approach Moab. The urge to rubber-neck is extreme, and needs to be resisted: be a passenger if you can. Eventually, UT 128 ends at US 191, a few minutes north of Moab.
Moab is home to the Semi-Annual Jeep Safari, which can give you some wild rides with difficult obstacles. Go 4-wheeling on the trails that stretch just outside the city. Many trails are a less than a few miles away, while some may take a short while to find and can be tricky. Trails rank from easy to difficult.
In summer time, Moab can get very hot. Drink extra fluids as needed. If you plan to go off-roading or camping out on the trails, take at least one gallon of water per person per day.