Warnings

on a gantry at Denver Sluice. This rather flat part of the country, known as The Fens is shielded from flooding by a complex system of artificial waterways and pumps that take water from low lying areas to slightly higher areas to drain away, either inland or to the sea.

A short perusal of the map using satellite view will give you some idea, and it is all the more remarkable that this monumental task was done in the 1650s, by legions of men under the inspired guidance of Dutchman Cornelius Vermuyden.

The green floats are strung across the water to prevent craft from straying too close to the gates which control the flow of water to a lower level behind where I was standing.