Athrad Poros was the name of a ford and town that lay one hundred and forty miles upstream from river Poros's confluence with the Anduin, where the Men Ithilien crossed it from north to south. The ford lay just below a fork in the main course of the river, whose arms branched north into Ithilien and towards the Ephel Duath, some sixty miles further east, situated just south of where the river forked into two arms, the northern being called the Ethraid.
The town was an important stopping point for the landward trade to the south. It began as a military garrison whose purpose was to guard the border between the fledgling Realm-tn-Exile and the sphere of Umbarean influence beyond. This outpost gradually acquired civilian features during the time of the Ship-kings, as the northernmost reaches of Haradwaith were transformed into the province of Harondor. With the opening of the Harnen corridor, Athrad Poros suddenly became a critical juncture for the landward trade route with Near Harad and Khand, and grew in size accordingly.
Athrad Poros received official township status in T.A. 1051, following Ciryaher Hyarmendacil's final victory over the lords of Umbar, and continued to be an important center of trade until the loss of Harondor during the Second Wainrider War in T.A. 1944. After that war, Athrad Poros was reduced again to a military garrison, since so many of its civilian inhabitants had been dependent for their livelihood on the now severed landward trade route.
In T.A. 2885, Athrad Poros was destroyed by invading Harwan forces from Al Amrûn (who were later driven back over the river by Túrin II of Gondor), but the garrison was never re-established while the Third Age lasted. Soon alter the War of the Ring, Athrad Poros was reoccupied and became a spearhead for Aragorn Elessar's reconqucst of Umbar. After his victories in the south, the new king entrusted the ford and its garrison to Prince Faramir of Ithilien.