A D-shaped barrow comprises a mound up to about 20m by 20m, built of soil and/or stones, which in plan resembles the letter "D" (one long straight side, two short straight sides, and a curved side) and which covers one or more burial deposits. The long straight side appears to represent the front of the monument and here the mound is edged by a facade. The burial deposits may be contained in a chamber which opens from the middle of the facade. Local materials were used in constructing D-shaped barrows and this gives rise to some regional variations in general appearance.
As field monuments, D-shaped barrows may be recoginzed as earthworks or as cropmarks, although in all cases positive authentication can be difficult without excavation. The main causes of confusion are with various classes of round barrow (especially bowl barrows), oval barrows, long barrows, and portal dolmens.
Specifically excluded from the class of D-shaped barrows are small long barrows which, although they may have similar kinds of burial deposit, usually have mounds which are of quite different proportions and concave rather than straight facades.
Available evidence suggests that D-shaped barrows were primarily funerary and/or ceremonial monuments, and as such probably overlapped in function with several other classes of contemporary monuments, notably long barrows and oval barrows.