The River Exe is a river in England that rises at Exe Head, near the village of Simonsbath, on Exmoor in Somerset, 5.2 miles (8.4 km) from the Bristol Channel coast, but flows more or less directly due south, so that most of its length lies in Devon. It flows for 60 miles (96 km) and reaches the sea at a substantial ria, the Exe Estuary, on the south coast of Devon. Historically, its lowest bridging point was the Old Exe Bridge in Exeter, the largest settlement on the river, but there is now a viaduct for the M5 motorway about 2 miles (3.2 km) south of the city centre.