Castel del Monte, Apulia Italy

Castel del Monte is a 13th-century citadel and castle situated on a hill in Andria in the Apulia region of south east Italy. It was built during the 1240s. when we went there we were told of a crafty defence built into it.

the secret was in the towers. The staircase went up anticlockwise so any invaders could not use their sword arm as it was against to centre column going up defenders could use theirs on the way down.
But that is not all, oh no. Only one of the 8 turrets had access to the roof. crafty or what