the Teifi (ordered from source to sea) are as follows: Afon Mwyro, Nant Glasffrwd, Afon Meurig, Afon Fflur, Camddwr Fach, Camddwr, Brennig, Nant Carfan, Afon Brefi, Nant Digonest, Nant Clywedog, Ffrwd Cynon, Nant Gou, Nant Dulas, Nant Hathren, Nant Eiddig, Nant y Gwragedd, Nant Dolgwm, Afon Granell, Afon Duar, Nant Hust, Nant Ceiliog, Nant Caradog, Nant Cwm-du, Nant Cledlyn, Nant Fylchog, Afon Clettwr, Nant Wern-macwydd, Gwenffrwd, Afon Cerdin, Afon Tyweli, Nant Merwydd, Hoffnant, Afon Gwr-fach, Afon Siedi, Camnant, Nant Bachnog, Nant Iago, Nant Bargod, Afon Cynllo, Afon Cwm-wern, Nant Halen, Afon Arad, Nant Sarah, Afon Ceri, Afon Nawmor, Afon Hirwaun, Afon Cych, Afon Eifed, Nant Arberth, Afon Morgenau, Afon Plysgog, Nant Rhyd-y-fuwch, Afon Piliau, Afon Mwldan, Nant Degwen, Nant-y-ferwig. Geology and landscape The Teifi and its tributaries are underlain by ancient Ordovician and Silurian mudstones which have been extensively glaciated during the ice ages. The resultant landform is one of gently rolling hills supporting a range of agriculture in which dairy and sheep farming dominate. Ceredigion had the reputation of supplying London with its milk in the 19th century. The landscapes of the Teifi valley are very attractive and the Teifi is considered by many to be one of the most beautiful rivers in Wales. Teifi Pools, the source of the Teifi, are a series of small upland lakes left by past glacial activity. The lakes are acid in nature. Some have been enlarged by damming and now provide a source of drinking water. The very extensive raised mire above Tregaron acts as a huge sponge at the head of the river and evens out extremes in flow. Rapids and waterfalls are uncommon but the examples at Henllan and, especially at Cenarth, are noteworthy and have been extensively photographed and painted because of the beauty of the landscape. A dramatic painting of the falls was made by Frank Miles and is now at Nottingham City Museum. Miles's father inherited Cardigan Priory from his father, Philip John Miles, but lived in Nottinghamshire as Rector of Bingham. The river enters a narrow gorge between Llechryd and Cilgerran, the sides of which are thickly wooded with a distinctive under-storey flora of wood rush. SSSI The Teifi has been designated as a Site of Special Scientific Interest (SSSI) since December 1997 in an attempt to protect the rare and unique features and species within it. This SSSI has been notified as being of both