Curious about pushing open doors that are usually closed? The Journées du Patrimoine (Heritage Days) are back, revealing the little-known treasures of the Île-de-France region. This year, don't miss the ultra-privileged opening of the Hôtel de Charost, the splendid residence of the British Ambassador, which celebrates its 300th anniversary on Saturday, September 20, 2025 - by reservation only, of course!