The lake is famous for its coarse fishing (particularly pike), watersports, the afanc (a monster nicknamed 'Gorsey') and has the only example of a crannog in Wales.

The lake is a Site of Special Scientific Interest (SSSI) and has long been regarded as a place where fish and birds are found in unusually high numbers.

[6] More recently the skull of a pike of unknown weight, though undoubtedly large (35–40+ lb), was found on the shores of the lake in 2004; it was taken away by the Environment Agency for age testing.

It is constructed of massive planks of oak behind which was built a dwelling platform formed from layers of stone, soil and brushwood.

Finds included a high quality textile and a bronze hinge from an 8th–9th century reliquary decorated in a style similar to that seen in Ireland.

The Mercian army seized and burnt the royal fort on Llangorse Lake, and took the Queen of Brycheiniog and thirty-three others captive.

[13] In his diary of the 1870s, Francis Kilvert noted several visits to Llangorse Lake, including a July 1878 outing in the company of his father, when the pair caught a brace of perch in an hour.

The earliest known surviving literary reference to the afanc or lake monster of Llangorse is in a poem by the 15th century Welsh poet or bard, Lewys Glyn Cothi (English translation by John Rhys):