Penrhyn Castle was originally a medieval defensible manor house, founded by Ednyfed Fychan. In 1438, Ioan ap Gruffudd was granted licence to crenellate and he founded the stone castle, when adding a tower house. Sited at the angle of a square courtyard, it defend the gateway, chapel and great hall. Sadly only the original spiral stairs can now be seen, with the vaulted basement and other masonry being incorporated into a dramatic 19th century neo-Norman mansion, founded by George Dawkins Pennant. 5 miles east is Pen-y-Mwd Mound and 11 miles south-west is Caernarfon Castle.