Heritage Days 2026 at the Yvelines' castles, the program for the 78.

Did you know? In Île-de-France, there are more than 250 castles. And for the Heritage Days, some of them throw open their doors to immerse you in the heart of their stories through often free tours, sometimes extraordinary openings and with special activities. The Yvelines are no exception. While the best known remains the Château de Versailles, the department 78 is brimming with treasures worth discovering. So why not take advantage of the 43rd edition of the Heritage Days to plan a route visiting the castles of the Yvelines?

Here’s a curated selection of the programs waiting for you this weekend of September 19–20, 2026 at the heart of the castles of the 78. All that remains is to plan your itinerary before heading to explore these architectural masterpieces and historic relics that deserve to be more widely known.

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Follow the guide and stay tuned: the page is updated as announcements come in and as we uncover new discoveries. Be sure to check the article regularly to discover more ideas for cultural outings in the castles during the Heritage Days 2026 in the Yvelines. And for more gems in Île-de-France, head here!