Birkhoff is a giant lunar walled plain that is located on the far side of the Moon, in the northern hemisphere.

This formation is an ancient impact site that has been heavily eroded, and the surface reshaped by multiple craters in the interior and along the rim.

The outer wall is bordered by the craters Carnot to the south, Rowland along the west rim, and Stebbins to the north.

What remains of the perimeter is now a rugged sloping rise along the inner wall, and the rim has been worn down until it is level with the irregular external terrain.

By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Birkhoff.