The moat of a 2,000-year-old city has been excavated in North China's Hebei province.

The 70-meter-wide and 4-meter-deep moat surrounds Wuyuan City, dating back to the Eastern Zhou Dynasty and has helped determine the limits of the city walls.

Located in Suning county of Cangzhou city, Wuyuan was listed as a protected historical and cultural site in 2003 and its excavation approved and funded by the State Administration of Cultural Heritage in 2015.

The dig, which started in September, has shown that Wuyuan was comprised of a square outer town protected by 1,800 meters of defenses around a smaller, inner town surrounded by 500 meters of walls.

The excavation is expected to last for another three or four years