The Great Wall of China

The Great Wall of China is a series of stone and earthen fortifications in northern China, built originally to protect the northern borders of the Chinese Empire against intrusions by various nomadic groups such as the Xiongnu from the north and rebuilt and maintained between the 5th century BC and the 16th century.

The Great Wall stretches from Shanhaiguan in the east to Lop Nur in the west, along an arc that roughly delineates the southern edge of Inner Mongolia. The most comprehensive archaeological survey, using advanced technologies, has recently concluded that the entire Great Wall, with all of its branches, stretches for 5,500.3 miles.

Before the use of bricks, the Great Wall was mainly built from rammed earth, stones, and wood. During the Ming Dynasty, however, bricks were heavily used in many areas of the wall, as were materials such as tiles, lime, and stone. The size and weight of the bricks made them easier to work with than earth and stone, so construction quickened. Additionally, bricks could bear more weight and endure better than rammed earth. Stone can hold under its own weight better than brick, but is more difficult to use. Consequently, stones cut in rectangular shapes were used for the foundation, inner and outer brims, and gateways of the wall. Battlements line the uppermost portion of the vast majority of the wall, with defensive gaps a little over one foot tall, and about 9 inches wide.

Forbidden City

The Forbidden City was the Chinese imperial palace from the Ming Dynasty to the end of the Qing Dynasty. It is located in the middle of Beijing, China, and now houses the Palace Museum. For almost five hundred years, it served as the home of emperors and their households, as well as the ceremonial and political centre of Chinese government.

The Forbidden City is surrounded by a 26 ft high city wall and a 171 ft wide moat. The walls are 28.3 ft wide at the base, tapering to 21.9 ft at the top. These walls served as both defensive walls and retaining walls for the palace. They were constructed with a rammed earth core, and surfaced with three layers of specially baked bricks on both sides, with the interstices filled with mortar.