Subways as bomb shelters - a part of life in Seoul

Subway stations in Seoul serve a dual purpose as shelters in case of aerial bombardment -- part of the city's answer to a perceived decades-long threat from North Korea. The city is home to 3,000 shelters -- including underground car parks and basements -- and periodic civil-defence drills ensure that most Seoul residents are well-rehearsed at making their way from the boardroom to the bomb-shelter.