Tokyo's Shinjuku district never goes to sleep.

Centered around a gigantic complex of railway terminals used by a mind-boggling 3.5 million commuters daily, Shinjuku has everything a megalopolis needs — world-class skyscrapers, shopping and night-time entertainment spots.

Shinjuku traces its roots back 300 years to the Edo Period, when it started out as a collection of inns where people traveling along Koshu Kaido, the old road linking the capital with the prefectures to the west, could rest for the night.