Dunnottar is a castle sitting on the north East coast of Scotland. It is surrounded by Cliffs on 3 sides and is a supurb defensive site. The seige is a recreation of an attack on the castle by Cromwell in 1652. in the siege 80 men defended the castle against a massive Army for severl months until they were starved out.
I've set it up. the castle is actually fairly medium to both defend and take. I've done both on "very Hard.