The Great Wall is the world's longest human-made structure, stretching over approximately 6,400 km (4,000 miles)[2] from Shanhai Pass in the east to Lop Nur in the west, along an arc that roughly delineates the southern edge of Inner Mongolia. It is also the largest human-made structure ever built in terms of surface area and mass.
Before the use of bricks, the Great Wall was mainly built from 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 30 cm (a foot) tall, and about 23 cm (9 inches) wide.
The steps that form the Great Wall of China are very steep and tall in some areas. Tourists often become exhausted climbing the wall and walk no more than a kilometre or two (around a mile).
Great Wall of China, which was chosen last month as top of the new seven wonders of the world, snakes its way across more than 6,400 km (3,980 miles) and receives an estimated 10 million visitors a year.
Now China's Wall become less and less Great!!
In the
news today about Great wall of China.
