An old commercial founded in the office of the nautical center.

An old fan, to ventilate the quarry, when there was the mushrooms culture in the quarry.

Quarries of Paris - The network located in the Val de Grace hospital.

The old quarries of the Val de Grace are medieval. They were exploited from the 13th century to 16th century.

In 1621, Anne of Austria asked Louis XIII transfer Benedictine nuns of the Convent of Bievre in Paris. The venue was the current location of the Val de Grace.

In 1638, the architect Francois Mansart began construction of a church and an abbey. In digging the foundations, he discovers that he is above old underground quarries. These voids are surveyed, mapped and consolidated. But Mansart spending too much money and who is the architect Lemercier completed the job.

For the purposes of work, workers have built a staircase to the underground quarries and give the name of Mansart.

Some training equipment to let the FBI playing war. Those equipment use an old bunker as main structure

Mushrooms culture in bags in the old quarry of Livry Gargan.

This is an old part of the Gard aqueduct, hidded by the forest.

Who's never dreaming of being inside a clock, like in some old movies?

The great dome of the Hôtel-Dieu de Lyon, also known as dome Soufflot. It is 31m high. In the old days, his role was to serve as a ventilation shaft for the patients' rooms.

Thanks to Argonaute for the lights (and to be so crazy to get down the hole with his candles)

Reservoirs of the Plaine Saint-Denis (here, the smallest tank), located under the France stadium are one of the largest type of construction. It can hold up to 165.000m ³ of water. The irregular shape of the pillars is due to the construction technique by molding (digging the soil, concrete injection and clearing the land around the pillar).