Llangollen Canal has 19 stone arches, each with a 45-foot (14 metre) span. Another aqueduct carries the canal over the River Ceiriog at Chirk, and there are tunnels nearby at Whitehouses, Chirk, and Ellesmere. The canal also forms the boundary on two sides of the Fenn's, Whixall and Bettisfield Mosses National Nature Reserve. In 2009 an eleven-mile section of the canal from Gledrid Bridge near Rhoswiel through to the Horseshoe Falls, which includes Chirk Aqueduct and Pontcysyllte Aqueduct, was declared a World Heritage site by UNESCO. The canal at Hurleston Junction rises from the Shropshire Union Canal main line, through four adjacent
Llangollen with Langolen in Brittany. Above the town to the north is Castell Dinas Brân, a stronghold of the Princes of Powys. Beyond the castle is the limestone escarpment known as the Eglwyseg Rocks. The outcrop continues north to World's End in Wrexham. The area nearest the castle is the Panorama Walk, and a monument to poet I.D. Hooson from the village of Rhosllannerchrugog can be found there. The ancient parish of Llangollen was divided into three "traeanau" ("traean" being the Welsh for "a third"): Llangollen Traean, Trefor Traean, and Glyn Traean. Valle Crucis Abbey was established at Llantysilio in about