https://en.wikipedia.org/wiki/Greenan_Castle

Greenan Castle is a 16th-century ruined tower house, southwest of Ayr in South Ayrshire, Scotland. Situated at the top of a sea cliff, it was originally a promontory fort converted into a motte-and-bailey in the 12th century. In the 15th century a tower house was built by the Lords of the Isles.

Photo and write-up by https://mastodon.scot/@McNige here: https://mastodon.scot/@McNige/110926238926867959