Mare Tranquillitatis is south of Mare Serenitatis. The above chart is the SW quadrant of Rukl Section 25 showing the site of Apollo 17, which landed in a valley between mountains to the north of Littrow.
North is up.
The eastern margin of Mare Serenitatis displays a distinctive albedo contrast. Dark mare materials separate the rest of Mare Serenitatis from the rugged highlands to the east. Littrow Crater is the partly flooded crater north of the valley. The Lincoln Scarp crosses both the valley floor and the surrounding highland material in North Massif. The mantle of light material that extends across the valley floor from the base of South Massif was investigated during the second EVA by astronauts Eugene Cernan and Harrison Schmitt.