France, Seine et Marne, Fontainebleau, the royal castle
Herstmonceux Castle, Hailsham, East Sussex.
Thirlestane Castle, Scotland
The caves below Nottingham Castle, UK including Mortimer's Hole, The River Leen ran below the castle in Medieval times and probably would have been used as a quick way in to the castle
Alnwick Castle, Northumberland where Harry Potter was filmed
Borthwick Castle, Scotland: Largest and best preserved surviving Medieval Scottish fortifications. 12 miles east of Edinburgh, remains in the Borthwick family ancestral seat, visited twice by Mary Qn of Scots, and attacked by Oliver Cromwell's forces in 1650.
Arundel Castle in Arundel, West Sussex, England
Hawthornden Castle is hidden in Roslin Glen near Edinburgh. It's privately owned by the Heinz Foundation and runs as a writers retreat. By Vic Sharp.