Southwest China's Chongqing is known for its mountains, architecture, and of course, hotpot. But did you know that Chongqing is also home to an "underground city" of old wartime air-raid shelters? Back in the 1930s, when the threat from Japan was at its most severe, air-raid shelters were built all over Chongqing. Now, many have been given a new lease of life, rebuilt into restaurants and bars. CGTN reporter Morag is in Chongqing to take a look.