The European Heritage Days are back on September 19 and 20, 2026, with one promise: to make history pulse to the rhythm of discovery. Île-de-France turns into a cultural playground, where curiosity and wonder become your best guides. Two open-door days to touch—the word is literal at times—the soulful essence of the most iconic places, and some that are more unusual, or even more secret. Châteaux, museums, gardens, curiosities... Heritage is experienced, heard, felt and savored in a different way. The perfect opportunity to explore History with a capital H, in a sensory, freely accessible format!
Did you know? There's an unusual troglodyte church in the Val d'Oise, just waiting to be discovered.
Did you know that in the Val d'Oise, the Church of the Annunciation at Haute-Isle is the only troglodyte church in the entire region? Carved directly into a chalk cliff and listed as a historic monument, it's an unusual nugget to discover. [Read more]
Why not dig a little deeper? Let's head for the Val-d'Oise (95), more precisely Haute-Isle, for a divine visit in both the literal and figurative sense: that of thetroglodyte church of the Annunciation. Carved out of the chalk rock between 1670 and 1673 at the request of Nicolas Dongois, the King's secretary, this church, the only one of its kind in Île-de-France, is the envy of the finest architectural gems. Entirely excavated from the cliff, only its masonry bell tower proudly protrudes from the hillside. At 26 metres long, 8 metres wide and 8 metres high, the nave is austerely mineral. Listed on the Inventaire Supplémentaire des Monuments Historiques since 1926, it continues to host services and ceremonies. As an added bonus, it's just a stone's throw from the troglodyte château of La Roche-Guyon!
The Invention of Photography
What is this image whose 200th anniversary we’re celebrating?
If Nicéphore Niépce is the undisputed pioneer of the still image, who really invented photography? Amid the parallel breakthroughs of Daguerre, Bayard, and Talbot, this piece traces the intertwined story of these genius inventors who gave birth to the eighth art.
Participation requirements: Limited to 40 participants - Free | No reservation required
Hours: Saturday, September 19, 2026 from 05:30 to 08:30, 10:30 to 11:15, 14:30 to 15:30 | Sunday, September 20, 2026 from 11:00 to 11:30
Dates and Opening Time
From September 19, 2026 to September 20, 2026
Location
Church of the Annunciation in Haute-Isle
144 Route de la Vallée
95780 Haute Isle
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More information
Saturday, September 20, 2025 - 10:00 ⤏ 13:00, 14:00 ⤏ 19:00 Sunday, September 21, 2025 - 10:00 ⤏ 13:00, 14:00 ⤏ 19:00
Did you know? There's an unusual troglodyte church in the Val d'Oise, just waiting to be discovered.
