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The Wikipedia item describes it well but basically boats enter from the River Weaver (above) and are lifted to the Trent and Mersey Canal (below) and vice versa.
The factory in the background is a chemical works producing potash and predates the boat lift.
The structure is brutally impressive but the winding gears (Citroen V cogs) and engine house (dating from its electric period) add a touch of elegance.
You can spot the "lift master" who controls the various gates and sluices and hopefully prevents 60 miles of canal cascading down into the River.
The image below shows our boat waiting for the gate to be raised to move in to the canal with the next load of passangers looking on.
The following day I went to Bitholmes Wood to find that the bluebells were a shadow of their display last year
So here's one from last year.