Less than one crater diameter to the south-southwest of Merrill is the similar Niepce, and to the east along the northern limb is the larger Brianchon.

The outer rim of Merrill is worn and the features are softened, but only a few impact craters lie along the edge and inner side.

The inner walls are uneven slopes down to the relatively flat interior floor.

This surface is marked by several small craterlets, including a pair near the midpoint.

[citation needed] By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Merrill.