River, bridge, or other?
The name "Araniant" appears as one approaches a bridge over the river between Windfells and Nan Laeglin. The name does not seem to exist in the lore. And, as I have not seen any mention of a name for this river elsewhere in the game, I speculate that the developers may have intended "Araniant" to refer to the river, rather than to the bridge.
The river flows west from the foothills of the Misty Mountains at Thror's Coomb, then south through the Mournshaws into Dunland. The current maps do not track its path beyond the Dunbog, but it is safe to assume that it would then either join the Isen somewhere west of the Gap of Rohan or flow directly into the Great Sea at some point between the mouths of the Isen and the Greyflood. I have read elsewhere that the River Adorn (flowing west from the White Mountains to the south) is the only tributary of the Isen attested by Tolkien. Thus, this feature appears to have been invented for the game. (Afterall, Dunland would be pretty dull if there were no good places to fish.) Halgoreth (talk) 20:04, 16 June 2014 (UTC)