Illustration par défaut

The Observatoire de Paris - PSL is participating in the Journées européennes du patrimoine 2026

17 juillet 2026

To celebrate Journées européennes du patrimoine, the Observatoire de Paris - PSL will be opening the doors to its two campuses in the Île-de-France region, one after the other. On Saturday, September 19, the event will take place in Meudon ; on Sunday, September 20, the Paris site will welcome the public. For this special occasion, these iconic scientific landmarks will reveal their full splendor. Reservations required.

Saturday, September 19 : in Meudon

This year we are celebrating the 150th anniversary of the founding of the Meudon Astrophysics Observatory and the 100th anniversary of its affiliation with the Observatoire de Paris. It is the cradle of French astrophysics, founded on the initiative of astronomer Jules Janssen (1824–1907). Today, the site plays a major role in the field.

The tour will allow you to enjoy the grounds—a former royal hunting estate—and to see its most iconic observational instruments :

  • the spectroheliograph, which has been used to monitor solar activity daily for over a century ;
  • and Europe’s largest astronomical telescope, which was recently restored.
A l'intérieur de la grande coupole de Meudon
A l’intérieur de la grande coupole de Meudon
Observatoire de Paris - PSL

Sunday, September 20 : in Paris

Founded in 1667 during the reign of Louis XIV, the Observatory is one of the world’s oldest astronomical observatories still in operation. This unique site embodies 360 years of astronomical research and exploration of the universe.

This is a rare opportunity to step inside its extraordinary historic building, designed by Claude Perrault (1613–1688), the brother of the storyteller, and to discover the precious legacy it preserves : antique telescopes, celestial globes, astronomical clocks, and many other fascinating instruments.

Highlights include :
• the Council Chamber and its painted ceiling,
• the Grand Gallery,
• the Paris Meridian Room,
• the rooftop terrace with a panoramic view of Paris,
• the Arago Dome and its large astronomical telescope from 1854.

Visite du bâtiment Perrault
Visite du bâtiment Perrault
Observatoire de Paris - PSL
Free tours (in French), by reservation only :

Reservations open on Wednesday, August 26, at 2:00 p.m. :



Led by astronomers from the institution, the tours last one hour.

These are events not to be missed for anyone who wants to understand today’s world through the lens of science. Because now more than ever, scientific literacy is an essential tool for becoming an informed citizen.