The Great Wall of China is a chinese fortification built gradually to protect China from Mongol and Turkish invasions of its northern borders. Its main purpose was not only to keep the invaders out but also to prevent them from escaping easily.
Its construction began in the 7th century BC. Its current form is mainly due to the Ming Dynasty that ruled the country from the 14th to the 17th century AD.
Its total length is 8,850 kilometers. Of these, 6,259 km are walls, 359 km are moats and 2,232 km are natural fortifications such as hills and rivers. With its forks, its length is 21,196 kilometers.
It is the largest human structure in dimensions.
Its first large section was built during the Qin Dynasty in the 3rd century BC. The second during the Han dynasty in the 1st century BC and the third was created from 1138 to 1198 AD, which was the period of the five dynasties and the ten kingdoms. The fourth took place from 1368 to 1620 from Emperor Hong Kong to Emperor Wang Li of the Ming Dynasty.
Each tower has visual contact with its previous and next tower so that everyone is immediately informed in the event of an attack. Even on the wall there are barracks and administrative centers at longer distances.
It is made of high strength materials.
[Source: el.wikipedia.org]
