This is Dunluce Castle on the north coast of Northern Ireland not far west of Giant's Causeway. We were on a tour of the coast with a visitor but only stopped to take some photos from the car park. We had seen the ruins many times and did not want to pay the fee, s new thing since we lived in Northern Ireland.
The castle was built in the 13th century by Richard de Burgh, 2nd Earl of Ulster. It was captured in the mid-1500's by Sorley Boy McDonnell and was abandoned in 1639 after a portion of the castle with several of its inhabitants fell into the sea.