Use sunset as your turnaround alarm.
Druid Arch does not look like the rest of Utah's arches. It is a squared-off slab standing at the head of Elephant Canyon, which is where the Stonehenge comparison comes from. Getting there means most of a day, sharing the first miles with the Chesler Park trail before turning up the canyon bottom through deep sand and loose rock that quietly drains your legs. The last quarter mile is the crux, steep with one ladder and some scrambling, and it is where people decide whether they want the view badly enough.
Stonehenge-scale arch at the head of Elephant Canyon.
Heat note: desert country - in summer start at dawn and carry more water than feels reasonable.
3+ liters water, broken-in boots, layers for weather swings, headlamp, real food (jerky, trail mix), trekking poles, first-aid kit, and an early start.
Make it a weekend: The Needles Campground (Squaw Flat) (Camping, 2 mi) · Willow Flat Campground (Camping, 18 mi) · Kayenta Campground (Dead Horse Point) (Camping, 25 mi) · Ken's Lake Campground (Camping, 32 mi)
More hikes nearby: Chesler Park Loop (Hike, 2 mi) · Grand View Point (Hike, 13 mi) · Mesa Arch (Hike, 18 mi) · Upheaval Dome Overlook (Hike, 22 mi)