Swasey is a small lunar

Moon

The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

 crater

Impact crater

In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...

 that lies along the eastern limb of the Moon

Moon

The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

. It lies near the southeastern edge of the Mare Smythii

Mare Smythii

Mare Smythii is a lunar mare located along the equator on the easternmost edge of the lunar near side. The Smythii basin where the mare is located is of the Pre-Nectarian epoch, while the surrounding features are of the Nectarian system...

, to the west of the walled plain Hirayama

Hirayama (crater)

Hirayama is a large lunar crater that is located on the far side of the Moon, just beyond the eastern limb. This region of the surface is sometimes brought into view from Earth during periods of favourable libration. However it is best viewed from orbit. This crater is located along the...

. About one crater diameter to the northeast is Hume

Hume (crater)

Hume is a small lunar crater that lies along the eastern limb of the Moon, along the southeast edge of Mare Smythii. It is located just on the far side of the Moon, but it is often brought into sight from Earth due to libration...

, and to the southwest is the merged crater pair of Kao

Kao (crater)

Kao is a small lunar crater that is located near the eastern limb of the Moon. It lies near the southern edge of the Mare Smythii, a lunar mare that continues onto the far side of the surface. This crater lies to the east-southeast of the crater Widmannstätten...

 and Helmert

Helmert (crater)

Helmert is a lunar crater at the southern edge of the Mare Smythii. It lies near the eastern limb of the Moon, and from the Earth it is seen nearly from the side. The visibility of this feature can be strongly affected by libration of the Moon in its orbit....

.

The outer rim of this crater is roughly circular, and a small crater overlies the northwestern side. This attached crater is also joined to the southeastern outer rim of the small crater Lebesgue

Lebesgue (crater)

Lebesgue is a small lunar crater that is located near the eastern limb of the Moon. It lies in the southeastern part of the Mare Smythii, to the southeast of the crater Warner. The southeastern rim of Lebesgue is attached to a small crater that overlays the northwest rim of Swasey, so that the...

.