Shinjuku ("new inn") is named after the taverns that popped up in this area in the late 17th century when the area became the closest town to Edo (Tokyo) from the Japanese Alps. Today this area still serves as a major hub with Shinjuku Station being one of the busiest train terminals in the world.
East Shinjuku has been the playground of Tokyo since the Edo period selling booze, food, arcades, and sex. The unlicensed red-light district in Kabukicho sits alongside the tiny bars, restaurants, and pachinko parlors where 500,000 people come each night to play in the neon glow.
West Shinjuku is the opposite end of the spectrum from its eastern half. This is where half of those that come to play, come to work. The area is filled with office blocks on some of the most expensive land in the country and was designated a fukutoshin, "secondary heart of the city," in 1960. The main attraction is KenzoTange'sTokyo Metropolitan Government Office completed in 1991 which is nicknamed 'tax tower' by some because of its US$1 billion price tag. The office does have some of the best views in Tokyo, from Mt. Fuji to Tokyo Bay on a clear day.