Great Mound

The geography of the regions northward of Beleriand is not well established, and in the case of the Great Mound we have very little information to work from. Its location is described as being 'in the midst of Anfauglith' (Quenta Silmarillion 20, Of the Fifth Battle: Nirnaeth Arnoediad). That could conceivably cover a vast area, so the location shown on the map is necessarily rather speculative.

Various references in The Silmarillion imply that the Great Mound held the bodies of Elves and Men, but not of Orcs (for example, the fact that it was the only green place in the desert of Anfauglith). However, this is not stated explicitly, and indeed it is said that the Orcs '...gathered all the bodies of those who had fallen in the great battle...' (Quenta Silmarillion 20, Of the Fifth Battle: Nirnaeth Arnoediad, our emphasis). That might be taken to suggest that the Orcs gathered the slain of their own kind, as well.

However, multiple references to the Great Mound in earlier material are clear that the Great Mound contained only the bodies of Elves and Men. This is stated numerous times within the contents of The History of Middle-earth, stretching from the very early Lost Tales to the much later Grey Annals. So, despite the ambiguous statement in The Silmarillion, it does seem to have been Tolkien's intent that there were no slain Orcs within the mound.