 and lasted until their demolition in the 1960s and 1970s.Sieges of city walls (along with naval battles) were portrayed on bronze 'hu' vessels dated to the Warring States (5th century BC to 3rd century BC), like those found in Chengdu, Sichuan, China in 1965.The walls of Han dynasty Chang'an were completed in 189 BC and covered a perimeter of 25.5 km while the later Eastern Han capital of Luoyang measured 4.3 km by 3.7 km.