Do you loveurbex, and the mysterious places that urban explorers bring to light? As part of the Journées du Patrimoine (Heritage Days), we're offering you the chance to live this experience to the full, by discovering disused spots, ruins and buildings usually off-limits to the public, whose secrets arouse our curiosity. You'll be able to explore the underbelly of the region without risk, and even set out to conquer those places that are the source of unanswered questions, and which you may regularly pass by without ever being able to enter.
The Journées du Patrimoine (Heritage Days) are an opportunity for enthusiasts and the curious alike to take advantage of a wide range of cultural opportunities. Paris and the surrounding region will not miss this opportunity to showcase its finest treasures through a vast program of free visits, unique experiences andexceptional openings.
For a weekend, the general public is invited to explore museums, monuments, castles, embassies, ministries, libraries, fashion houses, and much more to discover, through the programs, their histories and behind-the-scenes. Guided tours, special animations, workshops for young and old, imagination abounds to bring a weekend brimming with discovery to life. The next, 43rd edition awaits you this weekend of September 19-20, 2026.



Heritage Days 2026: Explore the Grand Cellar of the Priory of Conflans-Sainte-Honorine
Every autumn in Île-de-France, the Heritage Days fling open doors usually shut to the public: on September 19–20, 2026, dive into the region’s medieval history by stepping through the Grand Cellar of the Priory in Conflans-Sainte-Honorine. [Read more]



Explore Montgomery's tomb, a forgotten treasure, for Heritage Days 2026.
For the 2026 Heritage Days, head to Chevreuse in the Yvelines department to discover the fascinating mausoleum of Count Henri Georges de Pembroke and Montgomery, a little-known treasure of Île-de-France. [Read more]



Heritage Days 2026: explore the remarkable art village of Chomo in Seine-et-Marne
Heading to the Fontainebleau forest for Heritage Days 2026! Make your way to Achères-la-Forêt in Seine-et-Marne to discover Chomo’s art village, an offbeat open-air sanctuary of outsider art. [Read more]



Journées du Patrimoine 2026: unusual tour of Villenoy's cone-shaped anti-aircraft shelter (77)
Are you familiar with the Villenoy conical anti-aircraft shelter? Don’t miss the 2026 edition of Heritage Days to discover this nationally unique monument, located in Seine-et-Marne. [Read more]



The Sewer Museum opens its doors for free during Heritage Days 2026.
The Paris Sewer Museum is taking part in the new edition of Heritage Days! Meet on Saturday, September 19 and Sunday, September 20, 2026 for unconventional tours into the depths of Paris. [Read more]



Hauts-de-Seine: discover this enigmatic underground labyrinth for the 2026 Heritage Days
Craving an offbeat adventure? The King's Caves in Sèvres reveal their stone labyrinth for the 2026 Heritage Days in Île-de-France. [Read more]



Stroll through the heart of a ghost village in the Paris region for the 2026 Heritage Days.
Why did this small town in Val-d'Oise end up deserted in the 1970s? Come explore Goussainville's Old Village and its unique heritage during Heritage Days 2026. [Read more]



Inauguration of the Vanves ice houses and their unusual chapel for Heritage Days 2026
During the 2026 Heritage Days, set off to discover Vanves’ restored ice houses and their surprising neo-Romanesque chapel at the heart of Parc Frédéric Pic. A fascinating plunge into the quirky heritage of Hauts-de-Seine, on the doorstep of Paris! [Read more]



Heritage Days 2026: a vanished estate still leaves its mark in Châteaufort
In Châteaufort, the Domaine d’Ors preserves the traces of a former estate now ringed by protected natural spaces. A story to rediscover in the heart of the Chevreuse Valley on Saturday, September 19, 2026. [Read more]



Heritage Days 2026: The Nymphée Nymphée, a shell grotto in Viry-Châtillon (91)
Heritage Days are back for the weekend of September 19–20, 2026 in Paris and the Île-de-France region. It’s a chance to explore the Nymphée Nymphée, a mysterious shell-covered grotto waiting for you in Viry-Châtillon, Essonne. An offbeat discovery awaits! [Read more]



European Heritage Days: an exceptional tour of the Bois-Colombes air-raid shelter (92)
Attention history enthusiasts: a remarkable World War II relic awaits, offering exclusive tours. The Bois-Colombes air-raid shelter will host a special program for the 2026 Heritage Days on September 19 and 20. [Read more]



Heritage Days 2026 at the Royal Château of Montceaux: a glimpse into the Château of the Three Queens
How about we head off to discover the ruins of the Royal Château of Montceaux? This historic site in Seine-et-Marne opens its doors for the Heritage Days weekend on September 19–20, 2026. [Read more]



Heritage Days 2026: An exceptional tour of an air-raid shelter in Bourg-la-Reine, Hauts-de-Seine
During the 2026 Heritage Days, immerse yourself in history and discover a genuine World War II air-raid shelter in Bourg-la-Reine, on 19 and 20 September 2026. An exceptional visit that’s well worth the detour! [Read more]



A festive Sunday at Fort de Cormeilles-en-Parisis for Heritage Days 2026
Visit Fort de Cormeilles during the 43rd edition of Heritage Days, on Sunday, September 20, 2026. This former military fortress, now owned by the Île-de-France Regional Green Spaces Agency, opens its doors to families and history enthusiasts, free of charge, of course! Here’s the program. [Read more]



Heritage Days 2026 at Regard de la Lanterne in Paris: registrations open
Want to step off the beaten path during the Heritage Days? How about visiting the Regard de la Lanterne, a hidden gem in Paris’s 19th arrondissement? Registration opens on September 5, 2026! [Read more]



Heritage Days 2026 at the Maison du Fontainier, at the heart of Paris’s water history
Are you ready to dive into Paris’s history during Heritage Days 2026? What better way to do it than with a tour of the Maison du Fontainier, a flagship site in the city’s water history. Join us this weekend, September 19–20, 2026, to discover this unusual place. [Read more]



Journées du Patrimoine 2026 at the Catacombs of Paris: themed tours on the agenda!
The Heritage Days invite you all the way into the depths of Paris’ catacombs. Discover the program waiting for you in the capital’s underground on the weekend of September 19–20, 2026. Ready for themed guided tours through the heart of this enigmatic place in the capital? [Read more]



Heritage Days 2026: Explore the King's Cellars on an Underground Tour in Sèvres (92)
In Sèvres, history is hidden even beneath the city’s streets... During Heritage Days this weekend on September 19 and 20, 2026, explore the king's cellars. [Read more]
Dates and Opening Time
From September 19, 2026 to September 20, 2026