Hidden in Paris

The video game-themed street art first popped up in the French city.

This banal Parisian entranceway is not what it seems.

A subterranean shelter remains intact under a busy Paris railway station.

A modern-day Lascaux cave underneath Paris.

The spiral staircase hidden inside this giant Parisian column was likely built for Catherine de Medici's astrologer.

135 bronze medallions mark a French meridian line which once rivaled the hotshot Greenwich timeline.