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 deciding to add the "W", and at the same time as the numbers were altered, it ensured that all bridges carried a number on both sides. The work was due to be completed by July 2008, but there were delays due to manufacturing difficulties with the new castings. The Llangollen Canal passes through Hindford, Saint Martin's, Preesgweene, Chirk Bank, Chirk and Froncysyllte, and includes the Chirk Aqueduct, the Chirk Tunnel and the Pontcysyllte Aqueduct. This section was built as a navigable feeder and is both shallow and narrow. Some sections near Llangollen are too narrow for boats to pass each