The River Towy (Afon Tywi) flows down the broad Vale of Towy just beyond the northwestern margin of the Geopark. A handful of our rivers flow into it between Llandovery and Llandeilo.
From the Black Mountain via Carreg Cennen to Ffairfach.
The waters of the Cennen rise on the northern slopes of Tair Carn Uchaf and head west before turning sharply northwards beyond Trap.
A significant tributary of the Towy on the Geopark’s northern edge.
The river begins life as the Nant Gwydderig on the south-western slopes of Mynydd Epynt. It turns sharply westwards at Llywel and soon enters a deep valley followe by the A40 road. This wooded gorge, which divides the high ground of the Epynt from that of the Black Mountain, was probably cut by glacial meltwater during the ice age.
The Gwydderig joins with the Afon Bran at Llandovery and their combined waters enter the Tywi shortly thereafter.
A river with mythical associations
The source of the Afon Sawdde is Llyn y Fan Fach, the body of water associated with the legend of the ‘lady of the lake’. Its waters tumble steeply down 250m/800ft into Cwmsawdde on their way to meet those of the River Towy/Afon Tywi at Llangadog.
Where the river cuts through a series of tough Silurian and Devonian sandstones it has formed a narrow gorge, best developed for the 0.5miles/1km downstream from Pont-ar-llechau beside the A4069. This section of valley with its rocky river bed has been declared a site of special scientific interest (SSSI) for its almost complete – and certainly well exposed – section through the Silurian rocks of the region.