zoomphony.com

Shinjuku is a major commercial and administrative centre with a population density of 17,140 persons per km²! (Zurich has an average population density of around 4.046 persons per km².) In 2007 over 3.63 millions entries and exits were counted per day at the Shinjuku train station, more than at any other station in the world.

In my opinion it is one of the best places to get lost in the crowd and the anonymity, to feel the pulsation of the city and, of course, to observe people and passengers (and some lost foreigners).