Many artifacts from the Capital Museum's own collection, which were also unearthed in Tongzhou, are displayed. One of the items is a Liao Dynasty ceramic jar (pictured top) designed like leather bags used by nomadic people.

Kublai Khan's move to make Beijing the capital of the Yuan Dynasty (1271-1368) also gave a boost to Tongzhou's fortunes, especially after the construction of the Grand Canal, which links Beijing and Hangzhou, capital of Zhejiang province.

"The city expanded and the population also grew rapidly," says Gao. "And that created a greater need for food. Tongzhou then became a hub for food supply, which was transported via the canal from southern China."

According to historical records, there were as many as 13 state-owned silos in Tongzhou during the Yuan Dynasty.