The Caldon Canal (or more properly, the Caldon Branch of the Trent & Mersey Canal), opened in 1779, runs 18 miles from Etruria, in Stoke-on-Trent where it leaves the Trent and Mersey Canal at the summit level, to Froghall, Staffordshire. The canal has 17 locks and the 69-metre long Froghall Tunnel.