It takes its alternative names from the towns of Bideford and Barnstaple, located respectively on the rivers Torridge and Taw which flow into the bay.

The north-facing coastline east of Hartland Point is backed by steep wooded or rocky cliffs with no natural harbours; this section is sparsely populated.

The Northam Burrows area is managed as a country park, and comprises a grassy coastal plain with a shingle ridge and spit formed by a process of longshore drift.

The coastline between Saunton Sands and Baggy Point includes cliffs rising in places to 200 feet (61 m), comprising Devonian sandstones, shales, slates and limestones, many of which show dramatic folding.

[4] The popular national trail, the South West Coast Path, runs the entire length of the bay.