Shanghai has the world's largest subway network of 673 kilometers and 395 stations on 17 different lines. Shanghai Metro celebrates its 25th birthday on Monday. [Photo provided to chinadaily.com.cn]

A metro train runs out of a station in Shanghai. [Photo provided to chinadaily.com.cn]

A view of a metro train running in Shanghai. [Photo provided to chinadaily.com.cn]

A view of a metro train running in Shanghai. [Photo provided to chinadaily.com.cn]

A driver drives a metro train in Shanghai. [Photo provided to chinadaily.com.cn]

Member staff of Shanghai Metro check the trains. [Photo provided to chinadaily.com.cn]