The castle stayed in the family until 1951 it passed on to the National Trust, in lieu of death duties, at the death of Lady Janet Douglas-Pennant, together with 10.000 ha (40,000 acres) and a stunning  art collection, including the finest Old Master paintings.

The garden includes a walled garden with terraces, lawns, pergola and pools.

Penrhyn has a railway museum dedicated to industrial locomotives. The Pennant family were owners of the Penrhyn slate quarry at Bethesda, closely linked to the Penrhyn Quarry Railway, which was one of the earliest industrial railways in the world.

For visits and more detailed information, see website