Heritage Days 2025 at Parc aux Étoiles (78), the program

Take off now for a cosmic immersion at the European Heritage Days on September 20 and 21, 2025! This annual event turns the spotlight on sometimes hidden cultural treasures for two days, when Europe becomes a constellation of unique experiences. The event showcases history, art andarchitecture in a whole new way, opening doors that are not open to the public or closed during the rest of the year. Gone are the days of overly structured tours, and here we take off into cultural orbit, discovering unusual places, private mansions and emblematic museums.

Heritage Days in Paris 2025: secret, little-known or hidden places to discover this weekend
The Journées du Patrimoine are back again this year for an exceptional edition, taking place on Saturday September 20 and Sunday September 21, 2025. This not-to-be-missed cultural event offers you the chance to visit over 1,500 sites in Paris and the Île-de-France region. While the major museums and emblematic monuments are on the program, it's also an ideal opportunity to explore secret sites that are little-known or inaccessible the rest of the year. [Read more]

In this starry sky of discoveries, the Parc aux Étoiles at Triel-sur-Seine in the Yvelines (78) is undoubtedly a supernova. Born of theobservatory founded in 1973, this space museum took off in 1990 to become a veritable must-see for scientific culture. Here, 22,000 colorful stars sparkle in 34 black-lit display cases, offering a three-dimensional galactic spectacle. The Parc aux Étoiles, one of France's 48 Centres de Culture Scientifique, Technique et Industriel (CCSTI), invites visitors to explore the world ofastronomy,astrophysics andspace exploration through dioramas that bring the cosmos to life. Geosciences, life sciences and new technologies are also explored here, for a true plunge into the infinity of knowledge. With its large telescope and reproduction of a celestial vault, the Parc aux Étoiles promises an interstellar journey to the heart of the mysteries of the universe, all at your fingertips!

• To be read
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2025 Heritage Days program at Parc aux Étoiles :

• Guided tour of the museum area
  Saturday, September 20, 2025 - 13:30 ⤏ 14:15, 14:30 ⤏ 15:15, 15:30 ⤏ 16:15, 16:30 ⤏ 17:15, 17:30 ⤏ 18:15 | Sunday, September 21, 2025 - 13:30 ⤏ 14:15, 14:30 ⤏ 15:15, 15:30 ⤏ 16:15, 16:30 ⤏ 17:15, 17:30 ⤏ 18:15
  

  Discover space. Guided by a mediator, discover the Northern Hemisphere night sky and the Universe from its formation to the present day, then relive the great moments of the space adventure.

  For all ages 6 and up Duration: 45 min.

  
  
  
• Conference "Astrolabes, their history and manufacture".
  Saturday, September 20, 2025 - 14:00 ⤏ 15:00
  

  This ancient astronomical instrument is used to measure and calculate the height of the stars, hours, altitude... Invented in Antiquity, it was improved by the Arabs before reaching the West. Brigitte Alix is an astrolabe expert. She also makes them. She'll show you these instruments with their many dials, veritable jewels of precision. She will also be exhibiting her creations.

  
  
  

In short, an unmissable journey through heritage time and space!