The first, Afon Pabwyr, runs down from wooded Cwm Graiglwyd then under the town centre, Pant-yr-afon, to the beach; the second and larger, Afon Gyrrach, runs for about 4 miles from the northern slopes of Tal-y-Fan to the sea near Penmaenbach, passing through Nant Ddaear-y-llwynog (The Fairy Glen) and the old villages of Dwygyfylchi and Capelulo.