Himeji Castle is located in the center of Himeji City, about 50 kilometers west of Kobe and about 650 kilometers west of Tokyo. Himeji Castle is nicknamed "White Heron" Castle because of its white walls which are covered with white plaster. The reason for using white plaster is that it is fireproof. Like other surviving Japanese castles, Himeji Castle is built of wood, not stones, and so fire prevention is very important. As well as the fact that white plaster has fireproofing capabilities, it is also considered to be a strong reinforcement. Therefore it covers both walls and almost every outside structure from eaves to pillars. The castle is built on the top of a hill called Himeyama, which is 45.6 meters above sea level. The main tower, which is the center and the symbol of the castle, is 46.4 meters high. Himeji Castle is famous for not only this huge main tower but also the highly effective and complicated defensive design, which is just like a maze. Even today, with the route clearly marked, many visitors are easily lost. Fortunately, Himeji Castle has never been damaged by warfare, even during the Second World War. That is one of the reasons why Himeji Castle has kept its original form for nearly 400 years. In 1993, Himeji Castle was registered on UNESCO's World Heritage list, because it is a wooden castle structure of incomparable worth in the world and because the whole structure including towers, stone ramparts, and earthen walls are extremely well preserved.