Taxonomy is the science of classifying organisms. The system currently used by taxonomists is called the Linnaean taxonomic system, in honor of Swedish biologist Carolus Linnaeus (1707 â 1778). The Linnaean system breaks down organisms into seven major divisions, called taxa (singular: taxon).
When used by the Chinese to protect their land, this section of the wall has had many guards to defend China's capita, Beijing. Made of stone and bricks from the hills, this portion of the Great Wall is 7.8 meters (25.6 ft) high and 5 meters (16.4 ft) wide.
In this area, the regular way of building a double-sided wall is impossible. The lofty peaks serve as natural barriers on the other side. The height varies according to the terrain, often measuring 2-3.5 meters (6.6-11.5 feet) tall. A famous and steep single wall is located at Simatai Great Wall in Beijing.