Sleeping beneath the large square in front of the Notre Dame cathedral lies an archaeological crypt. Spanning the length of 117m and width of 28m, the crypt displays the remains of structures constructed during the Gallo-Roman period, including a 4th-century enclosure wall, the foundations of a medieval foundlings hospice, and several of Haussmann's original sewers. After the devastating Notre Dame fire in April 2019, the crypt and its surrounding square were closed off to the public; however, it is anticipated to reopen in spring 2020.