Heritage Days 2026: Discover the stunning Château de la Roche-Guyon (Val-d'Oise 95)

Did you know that a troglodyte castle is a fortress carved into rock or tucked into a cave? Pictures speak louder than words, and there’s no better way to grasp a topic than seeing it with your own eyes. So it’s decided: this weekend of September 19 and 20, 2026, head to the Val d'Oise to visit the Château de la Roche Guyon, the one and only troglodyte castle in Île-de-France!

This spectacular monument, with its rich history, can be visited during the Journées du Patrimoine weekend. A not-to-be-missed opportunity to enjoy this architectural curiosity.

The Journées du Patrimoine (Heritage Days) are back in Paris and the Île-de-France region. This major cultural event continues to surprise and delight. And rightly so: the Ile-de-France region is brimming with historical and artistic nuggets, and this special event is designed to help us visit them all!

• To be read
• This week's top picks for July 6–12, 2026 in Paris and Île-de-France

Every year, Heritage Days swing wide the doors to thousands of castles, museums, places of worship or power, backstage glimpses of theatres, and gardens. These days spotlight France’s heritage from every corner of the country, from the best known to the most secret... It’s a genuine celebration for all the curious, hungry for discoveries, and for smart outing ideas.

Discover what's in store at the château de la Roche Guyon during these Heritage Days 2026:

• History & Memory, "The Voices of the Casemates, 1944", created by Tomasz Namerła

  Tomasz Namerła’s installation offers a sonic and visual journey into the heart of the Roche Guyon castle’s casemates, which in 1944 served as Erwin Rommel’s headquarters to shield against enemy attacks and store ammunition. Just 200 meters from the castle, the La Roche-Guyon hospital (AP-HP) was also the stage for the quietly heroic act of Justinien Blazy, “Juste parmi les Nations.” In the cliff’s secret, where the black of flint cuts through the white of chalk, a delicate narrative unfolds, turning stone into a witness of History.

  Participation requirements: No reservation required

  Hours : Saturday, September 19, 2026 – 10:00 ⤏ 18:00 | Sunday, September 20, 2026 – 10:00 ⤏ 18:00

And find out what else is on in the Val d'Oise this weekend.

Heritage Days 2026 in Val d'Oise: an immersion into the heart of the 95's treasures
Heritage Days 2026 invites visitors to uncover the hidden treasures of Val d'Oise. From September 19 to 20, 2026, castles, museums, and churches will open their doors, revealing a historical and cultural heritage of extraordinary richness. [Read more]