Sitting impressively atop the rocky crag of central Edinburgh is the castle. This was definitely a good place to build in those tumultuous times when anyone was likely to attack at any moment and try to take your crown. Three sides of the extinct volcano are sheer drops thanks to once upon a time glaciers, and the black rock gives Edinburgh its distinctive dark and dour mood. If anyone did manage to make it up close enough to attack, then the thick walls of the castle itself would see them off. The last to try were Bonnie Prince Charlie’s army in 1745 but the palace is still headquarters of the Royal Scots Regiment so I suggest you visit in peace.