Named after Gerard De Kremer (Gerhardus Mercator) - Belgian cartographer, geographer, mathematician (1512-1594).
Mercator is a lunar crater on the southwestern edge of Mare Nubium, in the southwest part. It is located to the southeast of the crater Campanus, and the two are separated by a narrow, winding valley. The Rupes Mercator fault is tangential with the northeastern outer rim. (wikipedia entry)
