walled plain

American  

noun

1. a circular or almost circular area on the moon, sometimes with a floor that is depressed, usually partially enclosed by walls that rise to varying heights and that are usually lower than those of a crater.

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walled plain British  

noun

1. any of the largest of the lunar craters, having diameters between 50 and 300 kilometres

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Example Sentences

I now directed M'Allister to steer across the lunar equator into the southern hemisphere, and our attention was soon attracted by a very large walled plain on the eastward side of our course.

From To Mars via The Moon An Astronomical Story by Wicks, Mark

PHOCYLIDES.—This extraordinary walled plain, with its neighbouring enclosures, is structurally very remarkable and suggestive.

From The Moon A Full Description and Map of its Principal Physical Features by Elger, Thomas Gwyn

Usually the floor of a walled plain becomes brighter as the sun rises higher and higher in the sky, but Plato actually becomes darker under a high sun.

From To Mars via The Moon An Astronomical Story by Wicks, Mark

MANZINUS.—A walled plain, nearly 62 miles in diameter, with a terraced rampart rising to a height of more than 14,500 feet above the interior.

From The Moon A Full Description and Map of its Principal Physical Features by Elger, Thomas Gwyn

Moving almost due south, we passed the large but partially ruined walled plain known as Maginus.

From To Mars via The Moon An Astronomical Story by Wicks, Mark