Glanduin.

Glanduin : Border-River.

River Glanduin had its well in Hithaeglir some 30 Miles South from the Western Gates of Moria and ran West down and became the boundry between Eregion and Northern Dunland 80-90 Miles before it joined Sirannon near Ost-in-Edhil. the river was at its upper course fast and swiftly but as it came further down after the junction with Sirannon it soon became lost in the plains and disappeared in in the fens of Nîn-in-Eilph.