The Blueprints and the Underground Cistern

This is the last stop on the tour. Standing in front of the blueprints, let me share one more hidden place in the Opéra Garnier.

In The Phantom of the Opera, the hideout of the main character, Erik, is described as a place you can reach only by crossing an underground lake. Author Leroux is said to have drawn on the fact that the Opéra Garnier really does have an underground cistern.

There is a reason it exists. Soon after construction began, as workers dug out the ground and were laying the concrete foundation, groundwater burst through. So much water flowed out that draining it took a full eight months. Garnier therefore decided to build an underground cistern. Groundwater keeps coming the more you pump it out, but if you build a cistern and let the water level rise to a certain point, it reportedly stops seeping in. The cistern was built as a place for the groundwater to collect. The stage was built above it, leaving about 15 meters of clearance, and amazingly, the cistern is still pumped out about once every ten years when it fills with water.

To reach the exit, go straight on the left and head down the stairs. The gift shop is on the left, and you have to pass through it to get out. If you go down this passage before heading for the exit, you can see the Opéra Garnier once more.