I recently added a group of images titled "Arches National Park". Arches is one of my favorite parks to photograph . It was designated a National Monument in 1929 and a National Park in 1971. It consist of 76,359 acres of monoliths, arches, stone bridges, large sandstone pipe organs shaped by eons of weathering and erosion. Most of the formations are made of soft sandstone which erodes by wind and water. It is continually changing and at least 43 of these formations have fallen since 1977. In order to qualify as an arch it must be at least three feet in one direction. Last count I saw published was 2,000 qualified arches the greatest concentration in the United States.
The Icon of the park is Delicate Arch looping 65 feet out of an orange out cropping. The hike is somewhat strenuous but given enough time its well worth it. For photography purposes the best time to be there is sunset. if the light cooperates its a breath taking sight. Other note worthy arches and formations are Courthouse, Three Gossips, Park Avenue, Turret, Tower of Babel, Landscape, Balanced rock, the Windows section, Skyline Arch, Devils Garden, and many others. If your fortunate enough to be there right after a rain storm the light is usually fantastic.
Arches is located in Utah and the town of Moab is the gateway town. Moab has changed over the years since I have been going there. Its much busier and has become more tourist oriented. Still a great town to visit. There are many other places to visit when in the area. Canyon Lands, Dead Horse Point State Park, canyons with Anasazi ruins and other points of interest.
If you visit and plan to camp there are several areas you can camp in including the Park itself. Last I knew the Park camping was on a first come basis but I would call and check that out. The Park is open 365 days a year but can be mighty hot during the summer months. My favorite months to go are March-April and October-November. Its a great hiking park remember to take water and be careful as the sandstone can be slippery.