Sindarin: dol...head, hill, mount + Guldur (gul + tur, dūr: Sorcery Lord, rendered to Necromancer)
Sauron's fortress in Mirkwood. His lieutenant was the Nazgūl Khamūl.
It was called AmonLanc, 'Naked Hill', because no trees grew on its peak.
the highest point of the highlands of south-west Greenwood the Great.