[lunar crater] Lehmann is heavily worn with an irregular rim. A small double-crater overlays a portion of the northwest rim. The interior floor is nearly flat with groupings of tiny craterlets near the south and west edges. There is a gap in the southern rim which connects the floor to Schickard. A sinuous rille runs along the length of thi... Found on http://en.wikipedia.org/wiki/Lehmann_(lunar_crater)