A hidden door scribed with centuries-old soldiers’ graffiti has been discovered at a world-famous Kent castle. Historians found the Georgian piece at Dover Castle decorated with the initials of servicemen along with depictions of hangings and a detailed carving of a sailing ship. The door was found in St John’s Tower and dates back to about the 1790s – a time when a Napoleonic invasion of England was a real threat. English Heritage’s senior properties historian Paul Pattison says the markings provide unique insight into the mindset of troops during the period. “Scaling a ladder to the upper fl…