Situated on the alluvial plain of the Senne, the Abbey of Forest has always had to contend with rising water levels and flooding from the river that runs through Brussels. The site – naturally marshy – was radically altered to accommodate a major abbey, the remains of the final phase of which are still clearly visible today amidst the ‘industrial’ landscape of the lower part of the municipality of Forest. The nuns, who had been settled since the early 12th century on the site of Saint Alène’s martyrdom, developed an ingenious hydraulic system comprising large fishponds, canals and lakes, combined with tree plantations to contain the waters of the Senne and the neighbouring Geleytsbeek. Archaeological research carried out in recent years on the abbey’s surviving buildings, designed by L.-B. Dewez in the second half of the 18th century—the findings of which will be presented to you in the form of a conference—sheds new light on how the architect integrated his design into this alluvial landscape. The stream was thus diverted and channelled to create a large main courtyard, and a new domestic mill was built. Alongside the hydraulic works, sections of the abbey’s medieval enclosure wall have been unearthed, marking the boundary of the monastic enclosure and the parish cemetery of Saint-Denis Church. A brief site visit will conclude the conference.

Collaboration : urban.brussels, Museum Art & History, ABŸ, Commune de Forest / Gemeente Vorst

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.

Please note: for safety reasons, closed shoes are obligatory to access the site tour. Sandals and high heels are not permitted.

Practical information

Guided tours on Sunday 14/06/2026

Meeting point: place Saint-Denis, 1190 Forest

Maximum 25 persons per guided tour

Attention: closed-toe shoes are required for the site tour. Sandals and high heels are not permitted.

Reservation compulsory

Not accessible for PRM

Sunday 14/06/2026

Schedule of guided tours (Duration of the visit: 1,5 hour)

Guided tours only in French

10.30 (FR)

14.00 (FR)