This valley has a wild and remote feel hemmed in by the Mallerstang edge on one side and the distinctive Wild Boar Fell on the other. Two long distance walking routes follow the valley - the Lady Anne's Way and Pennine Bridleway.
This is a valley of great history as well as beauty. Near Outhgill you will find the ruins of 12 Century Pendragon Castle which legend associates with Uther Pendragon, the father of King Arthur. It has been widely repeated in many sources that the castle was ruined by fire several times. However recent research suggests this is possibly a misunderstanding that has been repeated, with the damage by fire probably occurring once during a Scottish raid in 1341. Pendragon was restored in the 17 Century by Lady Anne Clifford who is associated with many sites throughout the Dales.
There are also the ruins of a Pele Tower – a defensive building against Scottish raiders – at nearby Lammerside. Running down the length of Mallerstang is the Settle to Carlisle railway from its highest point at Aisgill, passing Kirkby Stephen and following the Eden Valley all the way to Carlisle.