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 water from the River Dee at Llantysilio (at the weir called "Horseshoe Falls"). After company mergers, the canal became part of the Shropshire Union System. Until recently it was properly called the Llangollen Branch of the Shropshire Union Canal, though it is now known as the Llangollen Canal. The canal supplied enough Dee water to supply Crewe and Nantwich, and when commercial traffic failed in the 1940s, it was its function as a water supply which kept it open. The canal is unusual amongst Britain's artificial waterways in having a strong flow (up to 2 miles per hour). Since the