Ilmaryen Keep once had been the frontier keep of an exiled Númenórean Noble in the Great Greenwood, in later ages the ruin had become the abode of a small force of thirty Blogrum-Hai Yrch, an orcish tribe who followed the Necromancer of Dol Guldur.The keep was located about eighty miles north of the Men-i-Naugrim on the northshore of a lake set within a series of hills at the western end of the southernmost chain of the Mountains of Mirkwood.