THE BASILICA NOTRE-DAME BOULOGNE-SUR-MER was built in the 19th century on the ruins of the medieval church. The current basilica is actually a double church. A classical church where you first enter and at the end there is an additional chapel under the dome. You can only find this type of layout in Paris: Dome des Invalides, where Napoleon is buried. During the reconstruction of the church, the discovery of the ancient Roman crypt underneath the church led to inspiration for the construction of a giant crypt under the entire surface of the basilica.

In the crypt you will find murals from different eras, including Romanesque and Gothic paintings, with a total surface of approximately 4000 m². The murals from the 19th century contain 160 figurative scenes dedicated to the characters of the church, the old and the new testament, the history of Notre Dame in Boulogne. Sculptures and archaeological finds with lapidary elements from Romanesque, Roman and Gothic art and architecture can be found in the crypt as well.