- Type: River.
- Length: 600 miles.
- Geographic Area: Rhovanion.
The Celduin (S."River Running") rose within the mountain Erebor, passed through the Long Lake, and emptied into the distant Sea of Rhûn. Most trade with the East came along the Celduin, for the Dorwinrim were among the only Easterlings not on hostile terms with the West.
- MERP:Northwestern Middle-Earth Campaign Atlas
- MERP:Northwestern Middle-Earth Gazetteer