There are a lot of stuff Chinese used to do or built that went
unnoticed or not given much attention
For example
Weiyang Palace ("The Endless Palace"), in (Han) Chang'an, now 7km/4
miles northeast of downtown Xi'an, Shaanxi province: imperial
palace of the prestigious Western Han Dynasty for two centuries.
This is the largest palace ever built on Earth, covering 4.8 km©÷
(1,200 acres), which is 6.7 times the size of the current Forbidden
City, or 11 times the size of the Vatican City.