Like many Devon rivers, the Teign rises on Dartmoor, near Cranmere Pool. Its course on the moor is crossed by several clapper bridges. It leaves the moor at its northern side, flowing beneath Castle Drogo in a steep-sided valley. It then flows southwards at the east edge of the moor. The river becomes tidal at Newton Abbot, and reaches the English Channel at Teignmouth. Its estuary is a large ria.