Morgulduin

The river Morgulduin (river of sorcery) was a river of Gondor that began in Cirith Ungol.

Flowing past Minas Morgul towards Anduin, it was met by the old Númenórean road from Osgiliath to the city in the Ephel Dúath.

It was crossed by the Harad Road with a bridge at the Crossroads where Frodo Baggins and Samwise Gamgee saw an old statue of a King of Gondor which had been defiled by Orcs. They later again followed the road towards the Tower of Cirth Ungol, led by Gollum.

The river had been defiled by the Nazgûl and was dark and dangerous.