Those of the north-west belong to the Mersey, and those of the north-east to the Don, but all the others to the Trent, which, like the Don, falls into the Humber.
The Trent & Mersey canal crosses the southern part of the county, and there is a branch canal (the Derby) connecting Derby with this and with the Erewash canal, which runs north from the Trent up the Erewash valley.
Bridges of this type have been erected at Portugalete, Bizerta, Rouen, Rochefort and more recently across the Mersey between the towns of Widnes and Runcorn.
The Runcorn bridge crosses the Manchester Ship Canal and the Mersey in one span of woo ft., and four approach spans of 552 ft.
North-west from London by the London & North-Western railway; and on the Grand Trunk (Trent and Mersey) Canal.