Built partly underground beneath the raised choir of the former 11th-century Romanesque collegiate church, a crypt was dedicated to the veneration of the relics of Saint Gudula. Its disappearance is the result of the considerable alterations the religious building has undergone since the 13th century, when a new, enlarged and widened choir in the Gothic style replaced the Romanesque one. A radical decision was taken to lower the floor level in the new choir and the ambulatory surrounding it, which inevitably led to the demolition of the crypt’s vaults; the crypt was subsequently abandoned and backfilled. Forgotten by collective memory, the decapitated remains were discovered at the end of the 20th century and remain in their excellent state dating from the 1270s. They are preserved beneath the current choir, protected by a concrete slab that allows public access. Visitors can discover the oldest preserved architectural monument in Brussels. The graffiti left by pilgrims is particularly moving to decipher.

Collaboration : urban.brussels, Church and Tourism Brussels, Société royale d’Archéologie de Bruxelles

Book your guided tour by sending an email to archeologie@urban.brussels, specifying the type of event/the site, the number of people, the time and the language.

Practical information

Guided tours on Friday 12/06/2026 and Sunday 14/06/2026

Meeting point: Cathedral of Saint Michael and Saint Gudula, 1000 Brussels

Maximum 10 persons per guided tour

Reservation compulsory

Attention: no rucksacks or other bulky items are permitted during the tour. The site is not suitable for young children or people with reduced mobility.

Friday 12/06/2026

Schedule of guided tours (Duration of the visit: 45 min)

On Friday, tours are available in French only and are exceptionally led by the archaeologist, Mr Michel Fourny, who excavated the crypt between 1989 and 2000 during the excavations carried out by the Royal Society of Archaeology of Brussels.

15.00 (FR)

16.30 (FR)

18.00 (FR)

Sunday 14/06/2026

Schedule of guided tours (Duration of the visit: 15 min)

14.00 (FR)

14.30 (NL)

15.00 (FR)

15.30 (NL)

16.00 (FR)

16.30 (FR)

17.00 (FR)

In addition, on an exceptional basis, on Sunday 14 June, admission to the treasury and the underground remains of the Romanesque tower will also be free. No guided tours are scheduled for the Romanesque ruins, but information panels are available on site.

The cathedral is open to the public on Fridays from 8.00 am to 6.00 pm, on Saturdays from 8.00 am to 5.00 pm and on Sundays from 1.00 pm to 6.00 pm.