The most impressive arch in Utah canyon county, excluding those enshrined in nearby Arches National Park, is Corona Arch.
A testament to the extraordinary size and beauty of Corona Arch is that it's sometimes called "Little Rainbow Bridge." It does resemble the famous natural bridge on an inlet of Lake Powell, but Corona is unique.
From Moab, the Corona Arch trailhead is closer than that of any arch in the national park. Yet you'll find Corona less crowded, because reaching it requires a 45-minute hike: a fun romp, mostly on slickrock.
Corona Arch is mammoth: 140 ft (43 m) high, with a span of 335 ft (102 m). Its setting is equally impressive: on the wall of Bootlegger Canyon, in a huge amphitheatre also containing Bowtie Arch.
Bowtie is a bonus sight. It appears that a haywire missile from a passing spacecraft blasted through the back wall of its deep alcove. If so, perhaps one of the alien pilot's many appendages accidentally bumped the ship's controls while all of his eyes were ogling Corona Arch.
Go to http://www.hikingcamping.com/photos-utah.php to see photos from Utah's premier canyon-country hiking trails, including two of the natural arches near Moab.
Go to http://www.hikingcamping.com/hike-moab.php to read about Done in a Day Moab, The Ten Premier Hikes. That's the book you need if you're a hiker, you're visiting Moab, and you want to see Corona Arch.
All ten hikes are boot-tested, certified spectacular by the Opinionated Hikers, Kathy and Craig Copeland, who've written guidebooks on many of the world's most spectacular wild lands.