Ffynnon Llugwy is a lake

Lake

A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...

 in the Carneddau

Carneddau

The Carneddau , are a group of mountains in Snowdonia, Wales. It includes the largest contiguous areas of high ground in Wales and England, as well as six or seven of the highest peaks in the country—the Fourteen Peaks...

 range of mountains in Snowdonia

Snowdonia

Snowdonia is a region in north Wales and a national park of in area. It was the first to be designated of the three National Parks in Wales, in 1951.-Name and extent:...

, North Wales

North Wales

North Wales is the northernmost unofficial region of Wales. It is bordered to the south by the counties of Ceredigion and Powys in Mid Wales and to the east by the counties of Shropshire in the West Midlands and Cheshire in North West England...

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It lies at a height of about 1786 feet (544 m) and covers an area of some 40 acres (16.19 ha). It has a maximum depth of 146 ft (45 m).

The lake acts as a reservoir

Reservoir

A reservoir , artificial lake or dam is used to store water.Reservoirs may be created in river valleys by the construction of a dam or may be built by excavation in the ground or by conventional construction techniques such as brickwork or cast concrete.The term reservoir may also be used to...

, providing water for Anglesey

Anglesey

Anglesey , also known by its Welsh name Ynys Môn , is an island and, as Isle of Anglesey, a county off the north west coast of Wales...

 and Bangor

Bangor, Gwynedd

Bangor is a city in Gwynedd, north west Wales, and one of the smallest cities in Britain. It is a university city with a population of 13,725 at the 2001 census, not including around 10,000 students at Bangor University. Including nearby Menai Bridge on Anglesey, which does not however form part of...

, and some water is also taken from its outflow, Afon Llugwy to feed Llyn Cowlyd

Llyn Cowlyd

Llyn Cowlyd is the deepest lake in North Wales. It lies in the Snowdonia National Park on the edge of the Carneddau range of mountains, at a height of above sea level. The lake is long and narrow, measuring nearly long and about a third of a mile wide, and covers an area of...

 via a series of leats.

Afon Llugwy which flows via Capel Curig

Capel Curig

Capel Curig is a village and community in Conwy County Borough, in Wales. It lies in the heart of Snowdonia, on the River Llugwy, and has a population of 226...

 and Betws-y-coed

Betws-y-Coed

Betws-y-Coed is a village and community in the Conwy valley in Conwy County Borough, Wales. It has a population of 534. The name Betws or Bettws is generally thought to be derived from the Anglo-Saxon Old English 'bed-hus' - i.e. a bead-house - a house of prayer, or oratory...

 before becoming a tributary of the River Conwy

River Conwy

The River Conwy is a river in north Wales. From its source to its discharge in Conwy Bay it is a little over long. "Conwy" is sometimes Anglicized as "Conway."...

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