A millennial crypt hidden beneath flowerbeds and winding promenades? It’s the little-known treasure tucked away in the Abbey Gardens of Argenteuil, in the Val-d'Oise. From 16 to 18 October 2026, the National Architecture Days return to sweep through Île-de-France. This cultural rendezvous invites curious visitors of all ages to see our familiar landscapes with fresh eyes, to understand the art of building, and to peer beyond the iron gates of buildings steeped in history. Just a stone’s throw from the Seine, this green enclave houses the remains of one of the most prestigious monastic foundations in the history of the Île-de-France region.
Founded in the 7th century and later influential in the Carolingian and Capetian periods, the former Abbaye Notre-Dame d'Argenteuil illustrates the evolution of medieval monastic architecture, here dominated by Romanesque art. This 11th- and 12th-century style is defined by thick limestone rubble walls, barrel vaults or rounded arches, and capitals carved with restrained geometric and vegetal motifs. The fouilles archéologiques have uncovered the crypt and the substructures of the monks’ dormitories, revealing the austere geometric logic of northern Île-de-France abbeys.
To the west of Paris, the remains of an abbey have been rediscovered and are now open to visitors
In Argenteuil, Val-d’Oise, visitors can explore the remains of the Abbey of Notre-Dame within an excavated archaeological garden. Discovered at the end of the 20th century and protected as a Historical Monument, these ruins provide a captivating glimpse into the medieval heritage of the West Paris region. [Read more]
The place is steeped in romantic memory. This is where Héloïse, separated from Abelard after their thwarted passion, took the veil and became prioress in the 12th century. A stubborn legend holds that Charlemagne himself gave the Holy Tunic of Christ to the monastery, through his daughter Theodrade, though some scholars describe these as pious tales forged after the fact.
Building Around the Workshop — Envisioning the City of Tomorrow
From the Garden of L’Atelier, alongside Maria Lazaridou — architect and cultural mediator — participants explore how Argenteuil’s urban landscape has evolved and observe how architectures from different eras coexist within the same neighborhood. Starting from a base that represents the site’s environment (garden, abbey ruins, streets, and the L’Atelier building), each participant envisions and constructs a new building that integrates into this existing landscape. This new addition prompts participants to reflect on the forms, volumes, and uses of a contemporary structure.
Each participant leaves with their own creation.
Participation terms: Limited to 8 people at a time - Free | No reservation required
Schedule: Sunday, October 18, 2026 - 2:00 PM to 5:00 PM
This page may contain AI-assisted elements, more information here.
Dates and Opening Time
On October 18, 2026
Location
L'Atelier, Abbaye gardens
19 Rue Notre Dame
95100 Argenteuil
Route planner
To the west of Paris, the remains of an abbey have been rediscovered and are now open to visitors
