Penrhyn Castle is located just to the east of Bangor, on a promontory overlooking the Menai Strait. It was originally a medieval fortified manor house, founded by Ednyfed Fychan, who was the seneschal to the Kingdom of Gwynedd and served Llywelyn the Great and his son Dafydd ap Llywelyn. That original construction was destroyed in the building of the Neo-Norman folly that can be seen today.

The present castle was begun in 1822 by George Day Dawkins-Penrhyn, who’d inherited the estate from his cousin, the first Baron Penrhyn. The Penrhyn fortune was built initially on the backs of nearly 1000 slaves who worked sugar plantations in Jamaica and then, after the abolition of slavery in 1833, through the exploitation of generations of Welsh slate miners. By the late 19th century, over three thousand men worked the Penrhyn mine, the largest slate mine in the world.

The castle remains much as it was in the 19th century and is available for tours through the National Trust. To this day, the estate encompasses over 40,000 acres and includes the house, gardens, fields, and a small railway museum.