On the occasion of the Heritage Days 2026, the Paris Observatory, a premier center of astrophysical research, opens its doors to the public in the heart of the capital. Discover an exceptional heritage and one-of-a-kind observing facilities to explore alongside the astronomers on site.
A prestigious and historic site dedicated to astronomy and scientific research, the Paris Observatory was founded in 1667 and is, in fact, one of the oldest observatories in the world. It houses majestic buildings and ancient astronomical instruments, offering the curious a fantastic plunge into the history of astronomy.
Historic telescopes, astronomical clocks and celestial globes are just some of the period scientific instruments that visitors can admire. But in addition to its historic role, the Observatoire de Paris also continues to be a center for research and training in astronomy and astrophysics. Scientists of international renown carry out advanced research here, contributing to our understanding of the universe and its mysteries.
On the occasion of the 2026 Heritage Days, Sunday, September 20, come and discover the Arago medallions, the meridian and equatorial telescopes in the gardens, the room of talking clocks, the Council Chamber and its painted ceiling, the Great Gallery and its ancient instruments, the monumental Méridien room known as "Cassini Hall", the panoramic terrace with a breathtaking view of Paris, the Arago dome and its large astronomical telescope dating from 1855. Note that visits are by reservation!
Guided tour of the Paris Observatory
Come visit the historic building of the Paris Observatory. Founded in 1667, it is the cradle of French institutional astronomy, in uninterrupted operation for more than 350 years.
You will have the chance to explore its original structure, perfectly aligned to the four cardinal directions. It stands as one of the major monuments of French classicism, designed from plans by Claude Perrault, the renowned architect behind the Louvre’s colonnade.
Among the highlights of the visit (about 1 hour):
- The panoramic terrace and its breathtaking view over the capital,
- The Arago dome housing the great telescope dating from 1854,
- The monumental room, known as "Cassini," engraved with the Paris meridian,
- The gallery and its collection of antique instruments,
- The Council Room, where the governing bodies meet, with its painted ceiling and portraits.
Participation conditions: Meet at 98 Boulevard Arago, 75014 Paris — Free | Reservation required - https://www.billetweb.fr/journees-du-patrimoine-2026-observatoire-de-paris-psl
Hours: Sunday, September 20, 2026 — 12:00–17:00
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Dates and Opening Time
On September 20, 2026
Location
Paris Observatory
77 avenue Denfert-Rochereau
75014 Paris 14
Route planner
Prices
Free
Official website
www.observatoiredeparis.psl.eu
