Longomontanus - Moon: South Region
Rukl 64, Rukl 72, VTM G14
Longomontanus (145 km) is a large walled plain, though dwarfed by nearby Clavius. It has a dept of 4.5 km - very deep for a crater. The crater floor appears to be younger than the crater walls, which are heavily terraced. A current explanation is that debris from a mare impact entered and filled the lower reaches of the crater. The cluster of internal craters at the RHS have diameters ranging up to 16 km, with 'M' being the most prominent.

Longomontanus_IR_12-05-31 21-01-36_PSE_R