Beijing Sightseeing: Great Wall at Badaling

While China continually expanded south and sinicized its southern neighbors, it had no desire to expand north since the northern lands were not suitable for agriculture. The northern land, however, suited its nomadic inhabitants, who lived on horseback. They could be defeated in battle but the government could not easily defend the whole border against their raids.

Resources
	Guide Books: Beijing \| China

After the first emperor of the Qin dynasty unified China by overruning six other kingdoms, he decided to combine existing fortifications to protect the country from the northern tribes. The wall was built, rebuilt and extended over multiple dynasties until it reached the length of 6400km (longer than the width of the United States).

The wall wasn't just a fortress, it was also a highway that could be used to ferry troops over a mountainous terrain. Lookout towers are located regularly along the wall, the guards in each tower being able to signal other guards via fire.

The Great Wall performed its intended function admirably. It was never successfully breached by invading armies. A foreign army, the Manchus, did cross the wall but it was able to do so because they were invited in by a Chinese general who needed their help defeating a local uprising. The Manchus, however, decided to stay and founded the last Chinese dynasty, the Qing.

It is difficult to explain the immensity of it all to those who haven't actually seen and walked through a portion of it. While everyone knows it is long, one has to see the rollercoaster-like terrain to really appreciate the difficulty of building it. Steep drops and rises makes a even a short walk tiring. Stand from any tower and the wall just goes on forever in either direction. The construction material was primarily brick and stone. The mortar? Glutinous rice paste.

The Badaling section of the wall is in excellent shape thanks to extensive restoration. Recent additions such as cell phone towers and a Great Wall roller coaster are a minor blemish on an otherwise awe-inspiring landscape and one of mankind's greatest engineering achievement.