dont usually get into lunar as you may know, but its big bright it and the high cloud and unstable skies bring desparation into the equation, but whats this please...
It's proper name is Rupes Recta, but most people call it the Straight Wall.
It is a 110kms long and between 240-300m high and about 2.5 kms wide.
It is a gradual slope, not a sharp cliff
Ron