The Seoul Metropolitan Subway is one of the most heavily used subway systems in the world with more than 8 million daily trips.

Seoul Metro is a public corporation which runs the Seoul Subway. During 1970-2006, it was called Seoul Metropolitan Subway Corporation.

It is also one of the longest subway systems worldwide, running 287 km in length. The trains mostly run underground, but 30 per cent of the system is above ground.

Image: South Korean travellers walk past a television broadcasting North Korea's nuclear test at a railway station in Seoul. | Photograph:: Jung Yeon-Je/AFP/Getty Images.