I would sometimes wonder when I am on a street how many people used to leave their footprints here as I did. 

In China, we can still find the sites of the Song Dynasty’s flaggings in the cities such as Hangzhou and Guangzhou. At that time, people had already paved the street with brick-like flagstone and created different patterns. However, more and more ancient roads have been removed for the extension. People can hardly find something older than half a century on the streets of big cities now, and even towns are unstoppably urbanising now.