I'm one of those people who is still annoyed about that tiny but in a way significant detail. It makes Dumbledore more eccentric and off his rocker than he really was. It bothers me, and it always will. If that makes me a crazy HP fan, then so be it.
St Micheals mount, Penzance. Cross the crossway at low tide and explore the castle and its beautiful gardens. Legend says a giant threw the rocks into the sea in anger. Just make sure you time it right on the way back. The tide races in fast and can cut of the unwary walker, so take one of the many boats back