Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Vallis Alpes is a spectacular lunar valley feature that bisects the Montes Alpes range. It extends 166 km from the Mare Imbrium basin, trending east-northeast to the edge of the Mare Frigoris. The valley is narrow at both ends and widens to a maximum width of about 10 km along the middle stretch. The selenographic coordinates of this feature are 48°30 N 3°12 E / 48.5°N 3.2°E / 48.5; 3.2. The valley floor is a flat, lava-flooded surface that is bisected by a slender, cleft-like rille.