Lacus Spei (latin for "Lake of Hope") is a small lunar mare that is located in the northeastern part of the Moon's near side. To the north is the crater Mercurius and to the west-southwest lies Schumacher
The selenographic coordinates of this feature are 43.0° N, 65.0° E, and it lies within a diameter of 80 km. The main part of the lake occupies a region averaging about 50 km in diameter, with an extension leading to the northeast. The surface has the same low albedo as the larger mare features on the Moon, becoming lighter in hue near the edges. The only feature on this bay is the circular, cup-shaped satellite crater Zeno P. The crater Zeno lies to the east-northeast, closer to the lunar limb.