During World War II, a water scheme was devised for the town of Llangefni in central Anglesey.

These arrangements became redundant with the building of the Cefni Reservoir, which was completed in 1951, but the settling tanks and pumping station survive in Llangefni to this day.

The northeastern end of the reservoir and the immediate surrounding area have been designated as a nature reserve,[1] and as a further measure of conservation, a plantation of trees runs along its north shore.

[4] The reservoir is easily accessible from Llangefni, as well defined paths run from the town through the local nature reserve, The Dingle, one of the few ancient woodland sites on the island.

[1] In the summer of 2011, toxic blue-green algae were found in the reservoir and visitors were advised to avoid contact with the water.