Llyn Cefni
Llyn Cefni is a small reservoir in the centre of Anglesey which is managed by Welsh Water and Hamdden Ltd.
As a reservoir, it hold 400 million gallons of water. It forms an artifical lake under a mile north of the island's central town, Llangefni and is now the source of the River Cefni and of other smaller watercourses.
The lake and the immediate surrounding area have been designated as a nature reserve and as a further measure of conservation an artificial plantation of trees runs along its north shore. Also of interest are the tracks of the Anglesey Central Railway which although no longer used still run over an embankment which crosses the water.
The lake is easily accessible from Llangefni as well defined paths run from the town through the local nature reserve, the Dingle.
At the maximum length of 1.4 miles and a total water surface area of 210 acres, llyn Cefni is the second-largest body of water on the island, exceeded only by Llyn Alaw, also a reservoir.
The is a dam on the south-east edge of the reservoir next to which is a car park.