[1] Manilius has a well-defined rim with a sloping inner surface that runs directly down to the ring-shaped mound of scree along the base, and a small outer rampart.

The small crater interior has a higher albedo than the surroundings, and it appears bright when the sun is overhead.

[1] Like many of the craters on the Moon's near side, it was given its name by Giovanni Riccioli, whose 1651 nomenclature system has become standardized.

(Isabella, Queen of Spain),[5] and Johannes Hevelius called it "Insula Besbicus" after the island in Turkey now known as İmralı.

[6] By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Manilius.