Röntgen is a relatively large lunar impact crater that lies along the northwestern limb of the Moon.

The smaller crater Aston is separated from the eastern edge of Röntgen by only a few kilometers of terrain.

The outer rim of Röntgen has been heavily eroded by subsequent impacts, and it now forms an uneven, jumbled ring of ridges in the surface.

The interior floor of Röntgen is nearly level, with only a few patches of uneven terrain near the edges and a low ridge near the midpoint.

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