Yangguanzhai relics in Xi'an, Shaanxi province -- Yangshao culture, about 5,000 years ago. This photo shows a bottle found at the Yangguanzhai site. [Photo provided to China Daily]

Archaeologists uncovered remains of settlements with defensive systems, water conservation facilities and a public cemetery that appeared to be a structure of a city dating back 5,500 years in Yangguan village in Xi'an, capital of Northwest China's Shaanxi province.

Experts believed the findings date the establishment of Xi'an as a capital city 2,500 years earlier than previously thought.