Bourgon Castle is unique in that it is nestled in a lush green setting—the Bourgon Forest and its clearing.
The starry sky here is exceptional because the forest acts as a barrier against light pollution from nearby cities. Biodiversity is preserved here even at night! 
ANCPEN SKY BACKGROUND LUMINANCE MEASUREMENTS AT THE CHÂTEAU DE BOURGON SITE IN MONTOURTIER 53** Measurements taken during a new moon with a clear sky should yield values close to 21 or even higher.
These values indicate sky conditions that are highly conducive to astronomical observations and astrophotography.** I can confirm that the sky background luminance measurements I took with an SQM (Sky Quality Meter) device showed a value of 20.94 despite unfavorable conditions (a crescent moon and a completely overcast sky causing significant reflection off the cloud layer of light pollution generated by the city of Mayenne).
Paul BLU, honorary president of ANPCEN. The “Jour de la Nuit” festival will take place on October 1, 2011; organized by a coalition of several organizations. The event is intended both as an invitation to (re)discover the beauty of the night and as a public awareness campaign to promote the protection of nocturnal biodiversity, the starry sky, and energy conservation.
The widespread adoption of street lighting has, in fact, led to a new form of environmental nuisance, recognized at the Grenelle Environment Forum: light pollution. The natural cycle of day and night is being disrupted, thereby affecting nocturnal biodiversity and the ability to observe the starry sky.
This lighting, which is often excessive and unnecessary, also leads to waste and drives up energy bills. This could be an opportunity to reflect on the environmental and political implications of these issues.
Here is our recap of the night festival on October 1, 2011, at Bourgon Castle. This evening was a bit unusual because the film crew shooting on location extended their shoot until Sunday.
So we celebrated the night with about fifty people. It was a magnificent night; the weather was perfect, heat haze rose from the moat, and the esplanade in front of the castle, under the stars, drew people in like a magnet.
Our short walks in the forest gave us the chance to see the chestnut tree nominated for Tree of the Year (following a contest held by *Terre Sauvage* magazine in partnership with UNESCO). With its face naturally carved into the trunk, it looked almost human in the moonlight.
The owls treated us to a chorus of hoots, adding to the magic of the place and the night. We’d love to do it again next year. 