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 Canal as the branch was constructed. At Frankton Junction the Montgomery Canal, which is partially restored, heads southwards. For historic reasons the bridge numbering continues down the Montgomery Canal and a second bridge numbering series for the Llangollen Canal begins with Rowson's Bridge (which is numbered both 1W and 70). The "W" addition was part of a Mimimum Safety Standards scheme instigated by British Waterways, to avoid possible confusion, especially for emergency services, of having different bridges on the same canal with the same number. British Waterways consulted with the Inland Waterways Association and the Shropshire Union Canal Society before finally