Atar itself is a market town and gateway rather than a destination in its own right. The old quarter has traditional mud-brick architecture worth a look, and the weekly market on Mondays is lively and authentic. The Agadir of Atar — a ruined fortified granary on the plateau above the town — gives good views over the surrounding desert.
The real attractions are in the surrounding region. Chinguetti is 90km northeast across the plateau — a holy city of the Sahara with crumbling medieval library towers. Terjit oasis is a lush palm-lined gorge fed by desert springs, about 45km south. The nearby desert landscapes — dune fields, rocky plateaux, ancient caravan routes — are best explored with a local guide and a 4WD vehicle.