Before becoming a visitor site, the Camille Flammarion Observatory was a genuine think tank with its sights set on the sky. Nestled in Juvisy-sur-Orge, in Essonne, this unique venue testifies to the passion of a man who dedicated his life to bringing astronomy to the widest possible audience. On September 19 and 20, 2026, for Heritage Days, visitors will have the chance to discover this emblematic site of the scientific heritage of the Île-de-France region.
Established at the end of the 19th century, the observatory sits on a property acquired by Camille Flammarion, one of the era’s most renowned French astronomers. A prolific popularizer, he played a pivotal role in sparking the public’s fascination with the stars, the planets and celestial phenomena. His goal was simple: to make astronomy accessible to everyone, far beyond the confines of the scientific community.
The observatory still houses a number of items that recount this adventure. Here you can see in particular the dome that shelters an astronomical telescope about 240 millimetres in diameter, used by Camille Flammarion for his observations. The house, his office, his library, and a range of scientific instruments also help illuminate the daily life of the astronomer and the nature of his research.
Listed as a historic monument, the site is now managed by the French Astronomical Society, founded by Camille Flammarion in 1887. Its mission is to preserve this exceptional heritage while continuing to share the wonder of astronomy with the public.
Tour of the Flammarion Observatory in Juvisy
Guided tour of the Observatory, Camille Flammarion’s former residence, the 19th-century astronomer. A demonstration of the Great Telescope housed beneath the dome. Tours depart every 30 minutes with a guide.
Free exploration of the park: association stalls, live music
Participation guidelines: Groups limited to 18 people in the dome - Free | No reservation required
Hours: Saturday, September 19, 2026 — 10:00 AM to 1:00 PM, 2:00 PM to 6:00 PM | Sunday, September 20, 2026 — 10:00 AM to 1:00 PM, 2:00 PM to 6:00 PM
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Dates and Opening Time
From September 19, 2026 to September 20, 2026
