The inner wall of Atlas is multiply terraced and the edge slumped, forming a sharp-edged lip. This is a floor-fractured crater with a rough and hilly interior that has a lighter albedo than the surroundings. Floor-fractures are usually created as a result of volcanic modifications.
There are two dark patches along the inner edge of the walls; one along the north edge and another besides the southeast edges. A system of slender clefts named the Rimae Atlas crosses the crater floor, and were created by volcanism. Along the north and northeastern inner sides are a handful of dark-halo craters, most likely due to eruptions. Around the mid-point is a cluster of low central hills arranged in a circular formation.
By convention these features are identified on lunar maps by placing the letter on the side of the crater mid-point that is closest to Atlas.