A small (~6.9 kilometer square) section of the Mees Formation, attendant to Mees (~263.72°E, 16.71°N) and, at least at one point, a 1,645 meter deep crack in the highlands well to the north by northwest of Mare Orientale. It is also just barely in the libration zone that allows it be visible from Earth, albeit at a very steep angle. By all appearances it's a basin, a long lake instead of a basalt-flooded "Sea." Some evidence has been put forth that the relatively late impact that created Orientale was sufficient to cause the eruption of lava at places several times as far away from the impact, and the length of Mees is radiant from the spectacular Orientale impact zone. The area was not well surveyed forty years ago. LRO is plugging the gaps in our knowledge of the Moon in several dimensions.