Llyn y Fan Fach Llyn y Fan Fach Llyn y Fan Fach (Welsh meaning "Lake of the small hill") is a lake of approximately 10 hectares on the northern margin of the Black Mountain in Carmarthenshire, South Wales and lying within the Brecon Beacons National Park. The lake lies at an altitude of approximately , immediately to the north of the ridge of the Carmarthen Fans. It is the smaller of two lakes within this mountain massif: the slightly larger Llyn y Fan Fawr is about to the east. The lake is overlooked by several prominent mountain peaks, especially Picws Du and Waun Lefrith.
Tal y Fan 2,001 feet, confirming its status as a mountain. Bwlch y Ddeufaen separates Tal y Fan from the main Carneddau ridge, the closest summit on which is Carnedd y Ddelw. Pen y Castell is directly opposite to the south. Tal y Fan Tal y Fan is an outlying peak of the Carneddau mountains in North Wales. It is one of the four Marilyns that make up the Carneddau, the others being Carnedd Llywelyn, Pen Llithrig y Wrach and Creigiau Gleision. It is high, and lies midway between the Conwy valley to the east and Penmaenmawr on the coast to the north-west.