The village I grew up in has a cliff sided promontory called the "Green Castle" - turns out that 1000+ years ago it held a substantial Pictish fort. As a kid I've picked bits of charred wood out from where one of the sides where it is eroding away.

Was it burned down by enemies (a Viking siege?), by accident or on purpose. Nobody knows.

https://en.wikipedia.org/wiki/Green_Castle,_Portknockie

And there is also the (crazy) idea that I've had since I was a kid that the Tap o' Noth is Tolkien's Weathertop ;-)