The wild, remote landscape of the central Brecon Beacons seems an unlikely place to suddenly find the calm, lapping waters of a lake. But if you look north-west from Corn Du or Pen y Fan, just where the steep, northern glaciated slopes start to fall away more gently, Llyn Cwm Llwch captures the eye.
A legend passed down through generations tells the story of an enchanted island invisible from the shore of Llyn Cwm Llwch.
A passageway leading from a rock to the island was said to be open on May Day each year. Those who had the courage to pass through the doorway would find themselves in a beautiful garden on the island inhabited by fairies.
The fairies would play enchanting music, tell stories of future events, and present visitors with exquisite flowers and luscious fruit. But each guest was told nothing must be taken from the island.
But one May Day, a greedy visitor placed a flower he had been presented with in his pocket. When he emerged from the rock the flower vanished and he lost all his senses. Since that day, the door to the island has never opened.
Llyn Cwm Llwch is the best preserved glacial lake in South Wales and sits right at the head of the Cwm Llwch valley – part of the Brecon Beacons Site of Special Scientific Interest (SSSI) and a Geological Conservation Review (GCR) site.
Sites like Cwm Llwch and its lake have been given GCR status because they make a special contribution to our understanding of Britain’s geological history.
Take a walk
Discover Llyn Cwm Llwch for yourself by downloading one of our walks. The Cwm Llwch from Cwm Gwdi walk is a tough 8 mile (12.8km) walk taking in Pen y Fan and Corn Du, as well as the lake.
But if you don’t fancy taking on this hike, you can choose one of our shorter routes to the summit of Corn Du and Pen y Fan, and take in spectacular views of Cwm Llwch on a clear day.