5Dover Castle, Kent

Known as the “Key to England,” Dover Castle has played a vital role in defending the nation since the 12th century. Its commanding position on the White Cliffs made it a strategic stronghold during medieval times and both World Wars. Visitors can explore the Great Tower, the medieval tunnels, and the wartime secret tunnels used during the Dunkirk evacuation. With its blend of military history and coastal views, Dover Castle offers one of England’s most comprehensive castle experiences.