Windsor Castle
@Lorajay much older and further north, you are in the right country though
Warwick?
@Lorajay It is an 11th century coastal defence built by the Normans to repel Viking Invaders, one of the oldest still intact castles in England
@LenHazell53 I even cheated with Internet searches and can't find it. Hopefully one of your fellow countrymen will see that post and win.
Looks like Edinburgh Castle
@CarolinaGirl60 too far north, it is in England and was built to defend a famous Abbey, often pillaged by the Viking King Eric Bloodaxe.
Bamburgh
@Lorajay and we have a winner
@LenHazell53 Without Google and your excellent hints I would never have guessed it. I plan to post something very easy.
Santorini?
And we have a winner, now it is your turn.
Close but Lenhazel53 hit the nail on the head.