Amazing And Incredible Pictures Of Shanghai City Model. With over 20 million people in its extended metropolitan area, Shanghai is China’s most populated city. On the third floor of the Shanghai Urban Planning Museum, there is what probably is the world’s largest scale model of a city. This is a scale model of what Shanghai will look like in 2020. At over 1,000 square feet, it shows (1:2 scale) every single building in China’s most populated city, or at least every single building planned. As far as scale models go, I’m not sure you’ll ever find out quite as impressive as this absolutely enormous one depicting what Shanghai is supposed to look like in 2020.