Although the highest point of the hills, Haddington Hill, is less than 900 feet above sea level, the rugged and pathless nature of the area posed a substantial obstacle to armies advancing towards London from the North, and even as recently as [[World War II]], fortifications were built in the hills in preparation for the anticipated German invasion. | Although the highest point of the hills, Haddington Hill, is less than 900 feet above sea level, the rugged and pathless nature of the area posed a substantial obstacle to armies advancing towards London from the North, and even as recently as [[World War II]], fortifications were built in the hills in preparation for the anticipated German invasion. |