Helwan also spelled Hilwan or Hulwan or Holwan, is a city in Egypt and part of Greater Cairo, on the bank of the Nile, opposite the ruins of Memphis. Originally a southern suburb of Cairo, it served as the capital of the now defunct Helwan Governorate from April 2008 to April 2011, after which it was re-incorporated into the Cairo Governorate. The kism had a population of 643,327 at the 2006 population census. (wikipedia entry)
A crater is a circular depression likely created by an impact event. On Gaspra they are named after spas of the world.
Sorry, there hasn't been a good map made for this world yet :(