The Macau Peninsula has a gate built on the northern isthmus, for how long did it serve as a border?
Macau Peninsula Macau Peninsula is the most populous and historic part of Macau. It has an area of 8.5 km² (4 x ) and is geographically connected to Guangdong province, at the northeast, through an isthmus 200 m wide. The peninsula, together with the city centre of Zhuhai, sits on an island separated from the continent by distributaries of the Pearl River. The Border Gate (; Portuguese: "Portas do Cerco" ) was built on the northern isthmus. At the south, the peninsula is connected to Taipa Island by three bridges, the Friendship Bridge ("Ponte de Amizade"); the Macau-Taipa Bridge ("Ponte Governador Nobre de Carvalho"); and the Sai Van Bridge ("Ponte de Sai Van"). The longest axis extends 4 km from the Border Gate to the southwestern edge, Barra (媽閣嘴). There is a western Inner Harbour (內港), and an eastern Outer Harbour (外港). The 93 m Guia Hill (松山) is the highest point on the peninsula, which is, on an average, 50 to . Many coastal places are reclaimed from sea. The Historic Centre of Macau, which is entirely in the Macau Peninsula, became a World Heritage Site in 2005.
Great Wall of China The Great Wall of China is a series of fortifications made of stone, brick, tamped earth, wood, and other materials, generally built along an east-to-west line across the historical northern borders of China to protect the Chinese states and empires against the raids and invasions of the various nomadic groups of the Eurasian Steppe. Several walls were being built as early as the 7th century BC; these, later joined together and made bigger and stronger, are now collectively referred to as the Great Wall. Especially famous is the wall built 220–206 BC by Qin Shi Huang, the first Emperor of China. Little of that wall remains. Since then, the Great Wall has been rebuilt, maintained, and enhanced; the majority of the existing wall is from the Ming Dynasty (1368–1644).