The Axe then flows west through Mosterton and Seaborough before turning south and forming the county boundary between Dorset and Somerset.

At a point some 3 miles (4.8 km) north of Axminster it is joined by the Blackwater River and enters the county of Devon.

According to Historic England, the village of Axmouth, which is some 1 mile (1.6 km) inland, 'was ranked as a major port by the mid-14th century and accounted for 15% of the country’s shipping trade'.

The remains of a late medieval fishing boat can be seen at low tide in the river, just south-west of Axmouth village.

To its east, the estuary is flanked by the steeply rising land of the hills behind the Jurassic Coast and the Axmouth to Lyme Regis Undercliff.

[8][9] Prehistoric archaeology: The Axe valley has produced evidence for some of the earliest human (Palaeolithic) activity in the south-west of England.