http://tourvideos.com/ York is England's finest example of a medieval town, so well preserved that it has become one of the world's most interesting historic cities, with a rich mix of activities for the visitor. This fortified town is surrounded by high stone walls that protected it from attackers in the past and then from modernization. The walls, dating to the Middle Ages and still 95 percent intact, are nearly three miles long, making it the nation's longest continuous stretch of medieval fortifications. A hundred other towns in Great Britain had fortified walls, but only York has such a grand state of preservation. Moreover, it is the only place where the walls were constructed on top of an earthen mound, making them that much more imposing. In all of Europe there are only a few medieval walled towns standing today, such as Rhodes in Greece, Carcassonne in France, and York. The fortified walls played several very important roles in creating these miracles of preservation: Because the walls were built to protect the town by keeping out the enemy, the space within the walls was extremely valuable and fully developed with a dense concentration of buildings, narrow lanes and no wasted space, creating a fascinating urban pattern that is great fun to explore today. The walls also controlled trade by preventing smuggling, enabling the government to place a tax on goods that came through the gateways and generating revenues for the town to prosper. The same walls have kept modern construction out and made York a time capsule of the Middle Ages.