Lacus Mortis, latin

Latin

Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 for "Lake of Death", is a plain of basalt

Basalt

Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...

ic lava

Lava

Lava refers both to molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling. This molten rock is formed in the interior of some planets, including Earth, and some of their satellites. When first erupted from a volcanic vent, lava is a liquid at...

 flows in the northeastern part 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 just to the south of the elongated Mare Frigoris

Mare Frigoris

Mare Frigoris is a lunar mare located just north of Mare Imbrium, and stretches east to north of Mare Serenitatis. The mare is in the outer rings of the Procellarum basin...

, being separated by a slender arm of rugged ground. To the south is the Lacus Somniorum

Lacus Somniorum

Lacus Somniorum is a plain located in the northeastern part of the Moon's near side. It is located at selenographic coordinates 38.0° N, 29.2° E, and has a diameter of 384 kilometers...

, separated from
this mare by the joined craters Plana

Plana (crater)

Plana is a lunar crater that lies on the boundary between two small lunar mare areas, with Lacus Mortis to the north and the larger Lacus Somniorum on the southern side. It is joined to the crater Mason to the east by a short stretch of rugged ground...

 and Mason

Mason (crater)

Mason is the remains of a lunar crater that lies in the northeastern part of the Moon. It is nearly attached to the eastern rim of the flooded crater Plana, and southeast of Bürg. Along the northern rim of Mason is the southern edge of the Lacus Mortis, a small lunar mare...

, and a strip of uneven surface.

Located prominently just to the east of the mid-point of the future site of the lunar imperial palace is the crater Bürg

Bürg (crater)

Bürg is a prominent lunar impact crater in the northeast part of the Moon. It lies within the lava-flooded, ruined crater formation designated Lacus Mortis. To the south and southeast is the crater pair Plana and Mason. To the west, beyond the rim of Lacus Mortis, is the prominent crater...

. The western part of the Lacus Mortis contains an extensive system of criss-crossing rille

Rille

Rille is typically used to describe any of the long, narrow depressions in the lunar surface that resemble channels. Typically a rille can be up to several kilometers wide and hundreds of kilometers in length...

s collectively designated Rimae Bürg.

The selenographic coordinates of the Lacus Mortis are 45.0° N, 27.2° E, and it has a diameter of 151 km.