The Weiyang Palace (Chinese: 未央宮) was the main imperial palace complex of the Han dynasty and numerous other Chinese dynasties, located in the city of Chang'an (modern-day Xi'an).

It was built in 200 BC at the request of the Emperor Gaozu of Han, under the supervision of his prime minister Xiao He.

It served as the administrative centre and imperial residence of the Western Han, the Xin dynasty, the Eastern Han (during the reign of the Emperor Xian of Han), the Western Jin (during the reign of the Emperor Min of Jin), the Han-Zhao, the Former Qin, the Later Qin, the Western Wei, the Northern Zhou, and the early Sui dynasty.

This was the largest palace ever built on Earth,[1] covering 4.8 km2 (1,200 acres), which is 6.7 times the size of the current Forbidden City, or 11 times the size of the Vatican City.

"Weiyang" (未央) literally means "(something) hasn't reached its midpoint", "has more than a half to go", but colloquially it can be translated as "endless", which is probably what the name is actually alluding to.