We have now come to the River Hoarwell, that the Elves call Mitheithel. It flows down out of the Ettenmoors, the troll-fells north of Rivendell, and joins the Loudwater away in the South. Some call it the Greyflood after that. It is a great water before it finds the Sea. There is no way over it below its sources in the Ettenmoors, except by the Last Bridge on which the Road crosses.
- The Fellowship of the Ring (Book 1), Chapter 12
Located on the Hoarwell just west of the Trollshaws, the Last Bridge marked the middle point between Weathertop and Rivendell along the great East Road.
The origins of the ancient bridge are unknown. It might have been built as early as the First Age, although it likely saw modifications and repairs by the Northern Dúnedain as they maintained it throughout the Second and the Third Age.