Metro Bits is dedicated to “the most elegant way of travelling”: urban underground railways, usually called metros or subways.

“Nothing is visible of a metro system in the city streets except occasional large holes in the ground. Every day, millions of people get swallowed by such holes and, multiple times faster than they could walk, pop up again from other holes far away. When examining the inner workings of a metro system, you find tunnels connecting the holes, forming a perfect mathematical graph. Trains are pulsating perpetually through these hidden arteries, so this must be the urban bloodstream that makes the big city a living organism!”

The site contains photos of metro stations across the world, including a page dedicated to Paris.