St Andrews Castle
Where Cardinal Beaton was murdered in May 1546 by lairds avenging George Wishart's execution; a young John Knox was among those later sent to the French galleys after the siege that followed.
Plan around this: Museum currently closed; no access to the mine, countermine or foretower.
Before you go: Mine/countermine tunnels are narrow, low, and uneven — not suitable for claustrophobic visitors or those with limited mobility; unguarded clifftop edges in places.