This beach’s dramatic English name is based not just on its semicircular shape resembling a wide, open mouth. Its hellish dimension comes from a savage, south-westerly aspect that offers precious little shelter to sailors.
Llanengan, Gwynedd, LL53 7LG
This enormous 19th-century neo-Norman castle sits between Snowdonia and the Menai Strait. It's crammed with fascinating items, such as a one-ton slate bed made for Queen Victoria, elaborate carvings, plasterwork and mock-Norman furniture.
The Conwy RSPB nature reserve is a wetland on the east bank of the Conwy estuary, created from material dug out during construction of the A55 road tunnel.