Now go outside and look at the sky.
Yamanote 29 is a site project dedicated to an urban rail line.
Doesn't sound like much, but the Yamanote Line encircles the inner city of Tokyo and since its tracks are raised it allows for a great one-hour tour of the city, rumbling through busy shopping districts, along parks and graveyards and quiet residential sections.
If you spend any time in Tokyo you will find yourself more than once on the green Yamanote trains, forever circling this metropolis. It can be fascinating to follow this zen-like circle, but then again the trains are also often crowded to the point of bursting.
I have a love-hate relationsship with the Yamanote line myself and it is nice to see that I'm not the only foreigner who feels that way...