Great Wall of China

The Great Wall of China (<a href="/facts/Traditional_Chinese_characters/bBFLkuz7">traditional Chinese</a>: 萬里長城; <a href="/facts/Simplified_Chinese_characters/UcAD6xXs">simplified Chinese</a>: 万里长城; <a href="/facts/Pinyin/pUwjfMXg">pinyin</a>: Wànlǐ Chángchéng, literally "ten thousand <a href="/facts/Li_(unit)/M327CsjN">li</a> long wall") is a series of <a href="/facts/Fortifications/pyH0FXhH">fortifications</a> in China. They were built across the historical northern borders of <a href="/facts/Ancient_Chinese_states/xkJ5hacw">ancient Chinese states</a> and <a href="/facts/Imperial_China/TNqRSvQ4">Imperial China</a> as protection against <a href="/facts/Eurasian_nomads/DAsbkwqW">various nomadic groups</a> from the <a href="/facts/Eurasian_Steppe/mJlxBbxJ">Eurasian Steppe</a>. The first walls date to the 7th century BC; these were joined together in the <a href="/facts/Qin_dynasty/TeBU8Nh3">Qin dynasty</a>. Successive dynasties expanded the wall system; the best-known sections were built by the <a href="/facts/Ming_dynasty/p3bSVwUH">Ming dynasty</a> (1368–1644).
To aid in defense, the Great Wall utilized <a href="/facts/Watchtower/sJntp75a">watchtowers</a>, troop barracks, garrison stations, signaling capabilities through the means of smoke or fire, and its status as a transportation corridor. Other purposes of the Great Wall have included <a href="/facts/Border_control/ngScQKAz">border controls</a> (allowing control of immigration and emigration, and the imposition of duties on goods transported along the <a href="/facts/Silk_Road/TLBryY39">Silk Road</a>), and the regulation of trade. 
The collective fortifications constituting the Great Wall stretch from <a href="/facts/Liaodong_Peninsula/fyGhYQa5">Liaodong</a> in the east to <a href="/facts/Lop_Lake/TtswgwqY">Lop Lake</a> in the west, and from the present-day <a href="/facts/China%25E2%2580%2593Russia_border/mrL1xaXE">Sino–Russian border</a> in the north to <a href="/facts/Tao_River/pA3hE9cC">Tao River</a> in the south: an arc that roughly delineates the edge of the <a href="/facts/Mongolian_steppe/KoA4LHxb">Mongolian steppe</a>, spanning 21,196.18 km (13,170.70 mi) in total. It is a UNESCO World Heritage Site, and was voted one of the <a href="/facts/New_7_Wonders_of_the_World/WVpPKtKP">New 7 Wonders of the World</a> in 2007. Today, the defensive system of the Great Wall is recognized as one of the most impressive architectural feats in history.

Great Wall of China open-in-new

Great Wall of China