The Sainte-Chapelle is a chapel built on the Ile de la Cité, in Paris, at the request of St. Louis to house the Holy Crown, a piece of the Holy Cross and various other relics of the Passion that he had acquired.

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

Beside the stairs Mansart, whose name was chosen in reference to the architect François Mansart, author of many works of consolidation in the hospital of Val de Grace.

A plate shows the depth of the underground quarry with great precision: Height 58 feet 6 inches or 18 meters 9969.

The Palais de Chaillot was performed at the Universal Exhibition of 1937 by the architects Leon Azema, Jacques Carlu and Louis-Hippolyte Boileau, instead of the old Palais du Trocadéro. The Chaillot Palace is composed of two pavilions and two curved wings flanking the esplanade of human rights. The facades and roof of the palace, its courtyard and terrace staircase, its remaining home decor (except theater review) have been classified as historic monuments December 24, 1980. It houses several museums.

source: Wikipedia

Control Room of the NATO radar base, the fort of Mount Salbert.

Fort Lefebvre culminates at the top of Mount Salbert 650m altitude. It said a strong "Sere River". It was built from 1874 to 1877. On May 12, 1955, NATO reuses the fort to house a communications center and a radar base. The book is officially delivered to the Air Force ole March 26, 1958. The book "G" Air Defense Planning (DAT) has 7 radio antennas. The old fort is used as a barracks for soldiers.

The radar base is not exactly the strong, but under the fort. Access from the fort is a long staircase of 322 stairs that descends into a concrete wall strongly.

The site is no longer running quickly but it remains occupied by the army until 1972. The mayor of Belfort is the current owner. It secures the site is now a promenade.