Versailles goes dark this Saturday for Night Day 2026.

The Night of Darkness 2026 plunges a slice of Versailles into darkness this Saturday, October 10. On the Place d’Armes, facing the château, astronomy clubs set up their telescopes for a free viewing of the starry sky.

This Saturday, October 10, 2026, Versailles participates in Jour de la Nuit and dims a portion of its public lighting. In Yvelines (78), the Place d'Armes, right in front of the château, will serve as the meeting point for a free stargazing evening from 8 p.m. to 11 p.m.

A dozen telescopes are made available there by two associations of amateur astronomers. The idea is simple: fewer streetlights, more stars. And there’s something pleasantly paradoxical about the Sun King’s old display window quietly giving way to let the night sky shine.

What’s on the agenda for the evening in Versailles?

According to the official event brief, three activities are on offer this Saturday evening:

Stargazing from Place d'Armes, in front of the castle, with around ten telescopes from the Cassini and Magnitude 78 astronomy clubs, from 8:00 p.m. to 11:00 p.m.
Walking hike of about one hour to raise awareness of light pollution, departing at 9:30 p.m. from Place d'Armes, near the equestrian statue, then passing through Place Hoche, Place du Marché and Rue de la Paroisse. The goal: spot businesses and offices still illuminated after 10 p.m. and leave them a small note reminding them of the lights-out timings.
Observation of light pollution and the stars from the top of a four-storey tower on Rue du Plateau Saint-Antoine in Chesnay-Rocquencourt, at a private residence, with a toy telescope and binoculars. Limited places, by registration.

Why is Versailles turning off its lights?

The Jour de la Nuit is a national campaign against light pollution, coordinated by the association Agir pour l'Environnement. It aims to safeguard nocturnal biodiversity (insects, bats, migratory birds) and to remind us what a real night sky looks like. This year marks its 18th edition.

The issue isn’t just about symbolism. The law requires storefronts and offices to close from 1 a.m., but Versailles has moved that cutoff to 10 p.m. by municipal decree, organizers note. Hence the evening stroll, which feels like a small, citizen-led walk through the town center.

The evening is locally led by the Pousses de Versailles collective. For those looking to carry the commitment into daily life, the Veilleurs de nuit collective shares resources and actions year-round.

Who are the astronomers stationed opposite the castle?

Observations are led by the Cassini Club, a Versailles-based astronomy group with around forty active members and a regular program of public viewing nights. The name is no accident: Louis XIV invited the astronomer Jean-Dominique Cassini to head the newly established Paris Observatory.

Alongside it, Magnitude 78, based in Magny-les-Hameaux, has spent more than 30 years nurturing sky-watching and science outreach. The two clubs are no strangers to the Place d'Armes: they’ve been setting up their instruments there since the very first Versailles edition in 2021, which had already drawn several hundred curious onlookers.

Will the stars be visible on Saturday night?

On the astronomy front, the calendar is lining up nicely: the new moon falls right this Saturday, October 10. With no Moon to wash out the sky, the stars and planets will have their moment. The weather, of course, should be checked at Météo-France before you head out.

If clouds roll in, the evening isn't canceled for all that. Organizers note that both amateur and professional astronomers will stay on site to chat with the public and share their passion.

A few tips to make the most of it: wear warm clothing (October evenings bite quickly), bring a chair or a blanket, a small stool so kids can reach the eyepiece, and binoculars if you have them. The organizers also suggest a red-light torch, the bicycle-lamp type, which is gentler on eyes accustomed to the dark, and a sky map prepared in advance with an app like Stellarium. The volunteers are easy to spot in their yellow vests.

Who is this walk for?

No prior knowledge or equipment is required. Families, groups of friends, or solo visitors—stay ten minutes or the entire evening. It’s the kind of outing that sticks with kids: seeing a planet for the first time through a telescope is something you don’t forget.

To get there, the simplest option is the RER C to Versailles-Château Rive Gauche station, just a few minutes’ walk from Place d’Armes. Be sure to check the perturbations prévues ce week-end on the Île-de-France network before you head out.

More ideas to keep your head among the stars

If astronomy has sparked your interest in getting back into it, the Castor Supermoon 2026 will be the next date to mark for watching the sky from Paris and the Île-de-France. And for other outings that won’t cost a cent, our pick of 10 free activities in October 2026 is brimming with great ideas.

Need to finish planning the rest of your weekend? Our lineup of outings for October 9–11 is here to help.

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