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

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

In the neighborhood of the south pole lies the large walled plain of Newton, whose interior is the deepest known depression on the moon.

From Pleasures of the telescope An Illustrated Guide for Amateur Astronomers and a Popular Description of the Chief Wonders of the Heavens for General Readers by Serviss, Garrett Putman

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

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

That," I said, "is a large walled plain called Plato, and, being on a receding curve of the moon, it is seen from the earth foreshortened, so that it appears to be elliptical in shape.

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