Armathwaite Castle is in the village of Armathwaite, Cumbria by the River Eden. Originally built to defend against Scottish raiders in the 15th century, it was converted into a mansion and today is a Grade II* listed building. Details Armathwaite Castle was built in the 15th century on a strong point along the west side of the River Eden by the Skelton family, possibly by John Skelton in 1445.The castle was a four-storied pele tower and protected the Eden valley from Scottish raiders. In 1712 the castle passed into the Sanderson family–one of whom, Robert Sanderson, made the castle the centre of a collection of antiquities and relics–and from there to the Milbournes and in 1846 onto William Lowther, the Earl of Lonsdale. In the late 18th and 19th centuries the castle was converted into a mansion, faced with ashlar cut stone in a classical style, with an adjacent wing for offices. Today the castle is privately owned.