Penrhyn Castle Puzzle

Penrhyn Castle is a country house in Llandygai, Bangor, Gwynedd, North Wales, constructed in the style of a Norman castle. The Penrhyn estate was founded by Ednyfed Fychan. In the 15th century his descendant Gwilym ap Griffith built a fortified manor house on the site.
Data from: en.wikipedia.org