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
Trent and Mersey Canal and two smaller tunnels at Saltersford (since 2008 also one-way operation, alternating each half-hour), and Barnton to the "junction" with the River Weaver at Anderton Boat Lift near Northwich. After Anderton, the next major destination is Middlewich, where a junction with the 50 yard long Wardle Canal leads to the Middlewich Branch of the Shropshire Union Canal which gives access to Chester, Llangollen and (south on the 'Shroppie') a parallel route to Birmingham/Wolverhampton. South of Middlewich, having passed through Wheelock, the T & M climbs out of the Cheshire Plain via the 'Heartbreak Hill' locks (more traditionally known as the