The Macau Peninsula has a gate built on the northern isthmus, for how long did it serve as a border?
Portas do Cerco The Portas do Cerco is an area in Nossa Senhora de Fátima, Macau, China. Located on the northern tip of the Macau Peninsula, it is known by its border gate separating Macau from mainland China. The gate was built in 1849 to replace a crumbling wall that was erected in 1573 to mark the border of the Portuguese colony. It was the site of the Passaleão Incident, a clash between the Qing dynasty and the Kingdom of Portugal in 1849 over the death of Macau's governor Ferreira do Amaral. Led by Colonel Mesquita, Portugal won the small battle which led to the extension of Macau's border northwards. At the limit of said expansion, the Portas do Cerco was built with the inscription "A pátria honrai, que a pátria vos contempla" (Portuguese for "Honor your motherland, for your motherland looks over you") on the façade on its inner arch in 1849. For the next 155 years, the gate served as the border between Macau and China.
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).