The River Exe , from which Exmoor takes its name , rises at Exe Head near the village of Simonsbath , close to the Bristol Channel coast , but flows more or less directly due south .
Most of Exmoor 's length lies in Devon .
The River Exe , from which Exmoor takes its name , rises at Exe Head near the village of Simonsbath , close to the Bristol Channel coast , but flows more or less directly due south , so that most of its length lies in Devon .