Sit back, relax, and take a tour of the Moon's craters: Sinus Iridum - a plain of basaltic lava that forms a northwestern extension to the Mare Imbrium Ptolemaeus - a lunar impact crater measuring nearly 100 miles across Montes Apenninus - a rugged mountain range between Mare Imbrium and Terra Nivium Rima Hyginus and Rima Ariadaeus - two valleys that run parallel along the Moon's surface Aristarchus - the brightest crater on the Moon's surface, visible to the naked eye Hadley-Apennine - the east