|Location||River Aros, north of Doriath|
|Etymology||S. Aros (river-name) + iach "ford"|
|Events||Crossing of Aredhel, Maeglin & Eöl|
Arossiach, the Fords of Aros, was the ford on the upper reaches of the River Aros, where the long and perilous road through the valley of Nan Dungortheb crossed eastward into the lands of West Beleriand.
The River Aros had its sources in two streams that flowed southward out of the hills of Dorthonion. Where those streams met, an ancient east-west road crossed the upper reaches of the river at a ford. The ford marked the boundary between two regions. To the east was Himlad, and the other lands held by the sons of Fëanor. To the west was Dor Dínen, and beyond it the perilous valley of Nan Dungortheb.
The Fords of Aros seem to date back to the days before the beginning of the First Age, when the roads north of Doriath were safe to travel. After the coming of Ungoliant, and the raising of the Girdle of Melian, the lands west of the Arossiach became a haunted and dangerous place, and in later years the Fords were only used by the bravest or most desperate travellers.