Amon Lanc
From Tolkien Gateway
Amon Lanc (S. amon "hill" + lanc see article) was a hill in the southern parts of Greenwood the Great. After a millennium of the Third Age had passed, Sauron came to Amon Lanc and built a stronghold there. The hill and fortress were then together called Dol Guldur, and the wood it which it stood became known as Mirkwood.
