Adventurers traveling north from the Bree-land along the mostly-abandoned Greenway will encounter a truly formidable barrier to further northerly travel: the dark cleft of Cirith Núr. Knifing between the North Downs and the southern regions of the shadowed and mysterious lands of Angmar, this dark cleft once held waters flowing out of Emyn Uial in the West. Over the ages, this mighty river has since receded, leaving only the sharp cliff edges and the uncertain depths below.

In the wars long ago between Angmar and the realms of Arnor, the cleft was spanned by a majestic stone bridge and the town of Trestlebridge rose on the southern edge of the cleft to support travelers and trade, as well as the movement of Arnor's troops in the region. Soon, however, the town and its namesake bridge found itself trapped between the two mighty armies. In the latter days of the war, the bridge was destroyed by the retreating hordes from Angmar, and without the mighty span, the town dwindled and was all-but forgotten. In time, a new bridge was built atop the ruins of the old, and the settlement of Trestlebridge again grew from its ancient foundations. With the power again rising in Angmar, Trestlebridge and its sturdy bridge have once more become a major strategic focus in the war between the Free Peoples and the forces of Shadow.