Shropshire Union Canal links are to the Llangollen Canal (at Hurleston Junction), the Middlewich Branch (at Barbridge Junction), which itself connects via the Wardle Canal with the Trent and Mersey Canal, and the River Dee (in Chester). With two connections to the Trent and Mersey (via the Middlewich Branch and the Staffordshire and Worcestershire Canal) the SU is part of an important circular and rural holiday route called the Four Counties Ring. The SU main line was the last trunk narrow canal route to be built in England. It was not completed until 1835 and was the last major civil engineering accomplishment of
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