Hirayama is a large lunar impact 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.

This is a worn and eroded crater with multiple impacts overlapping the outer rim and the interior floor.

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

The names Tolstoy, Montesquieu, Longfellow, and Balzac were proposed for satellite craters Y, S, Q, and K, respectively, but were not approved by the IAU.