Through the underground floor of the Bourse, you enter the archaeological site 'Bruxella 1238'. The original cellars also house a technical area and stock space. The latter are not accessible to the public.
Bruxella 1238 (588 m²) takes you to the Brussels of 800 years ago. In 1988 excavations took place in rue Henri Maus and rue de la Bourse. These revealed three phases of urban development:
- A Franciscan monastery, built in 1238, stood until 1799.
Fact: Duke Jan I of Brabant – also known as the beer king Gambrinus (bastardisation of his Latin name 'Jan primus' or 'Jan the first') – is said to be buried under the church choir.
- The Butter Market, built in 1799 was located there until 1871. In 1813 the market was expanded and became a rectangular esplanade, planted with trees and surrounded by a gallery.
- The Bourse, which from 1871 took the place of the Butter Market – the time of the covering of the Senne and the construction of new streets and avenues. Fact: the architect of the Bourse, Leon Suys, initially wanted to build the new building exactly on the footprint of the monastery and the Butter Market, which would have destroyed all archaeological history under the streets. But he decided at the last minute to locate the building perpendicular to the avenue – much to the happiness of archaeologists today.