Llangorse Lake is the largest natural lake in Wales, and is situated in the Brecon Beacons National Park, near to the town of Brecon and the village of Llangors.The lake is famous for its coarse fishing, watersports, the afanc and has the only example of a crannog in Wales. Llangorse Lake is also one of the most mentioned sites in Welsh folklore. It is a site of international conservation importance.Due to the lake's long history of human activity, it has been known by several different names during its history, both in the Welsh language and in English: other names include the lake's original Welsh name, Llyn Syfaddon/Syfaddan, and Brycheiniog Mere. The name Llangorse Lake is comparatively recent.GeographyLlangorse Lake is a eutrophic glacial lake with a 5mi circumference covering an area of 327acre. The lake is 1mi long and 505ft above sea level. The lake is sited between the basins of the River Wye to the north and the River Usk to the south, and occupies a glacially scoured rock basin partly enhanced by morainic debris. The Afon Llynfi provides the main input of water into the lake and continues as the lake overflow stream. The lake has a maximum depth of 7.5m.