Crypte Archéologique

Museum in The Islands

Beneath the square in front of Notre Dame is the Archaeological Crypt. The 117m-long and 28m-wide area displays the remains of structures built on this site during the Gallo-Roman period, a 4th-century enclosure wall, the foundations of the medieval foundlings hospice and a few of the original sewers sunk by Haussman.

A highly worthwhile 30-minute audioguide costs €5.