Mare Smythii
Warner is a lunar impact crater that is located in the southern part of the Mare Smythii, near the eastern limb of the Moon. In this location the crater is viewed almost from the edge from Earth, and is sometimes hidden from sight due to libration. The crater lies just to the south-southeast of the very similar Runge. To the southwest is Widmannstätten, and to the south is the merged Kao–Helmert crater pair.