Subways

Tucked away in a London Tube station, this 1920s linear clock shows the time across the world all at once.

This 40-meter waterfall of light graces one of the most iconic stations in the Madrid metro network.

This subway station is named after a local legend about supernatural dancing cats.

One of London's lost rivers runs through a pipe over the tracks of this subway station.

This statue of one of the engineers who created the London Underground hides a ventilation shaft for the tube lines that run under the street.

An underground world of gorgeous, palatial metro stations designed as a nuclear shelter complex.

The only airport with a people mover system designed by Walt Disney Imagineering.

This metro station doubles as an unintentional paleontology museum.

A neighborhood represented by an apparent geocentric and flat-earth model of the Solar System is hidden in the subway of Madrid.

View the ancient remains of buildings and the ancient "River of Hades" before hopping on a train.

Designed by famed 20th-century architect Cass Gilbert, the future of this abandoned 1908 rail station is currently in limbo.

There are hidden patterns on the subway seats of some Stockholm metro cars.

Out of a labyrinth of abandoned tunnels and stops, this Queens subway station is arguably the most mysterious—if it exists at all.

The only example of a Paris Métro sign in use at a subway station outside of the French capital. 

A touching tribute to the "Queen of Soul."