The Great Wall Of China
The Great Wall we see today mostly dates back to the Ming Dynasty. The best-preserved and most imposing section is at Badaling in Beijing. The section, located outside the Juyongguan Pass, is made of large blue bricks and has an average height of 7.8 meters. Five to six horses can be ridden abreast along it. At regular intervals there is an arched door leading to the top of the wall. The walls are covered with many lookout holes, window embrasures and castellated crenels. Beacon towers were also built at fixed intervals for passing on military information. All these indicate the important role of the Great Wall in military defense.