EXPA – Galileo's Sky

The stars above Castelmagno

In Castelmagno, the highest municipality in Valle Grana in the Province of Cuneo, darkness is not an absence but a treasure. Far from the lights of the plains, the night sky of this Occitan valley in Piedmont is considered one of the darkest and least polluted in Italy—a heritage that Galileo's Sky celebrates every February with an evening entirely dedicated to stargazing.

The event takes place at the Rifugio Maraman, on Via Colle del Mulo, and is organized by the Ecomuseo Terra del Castelmagno as part of the EXPA – Experiences for Passionate People festival, a calendar of cultural, naturalistic, and gastronomic events that brings the valley to life from February to November.

Astronomy and scientific outreach

The heart of the evening is the sky observation guided by leading astrophysicists and science communicators. Researchers from the National Institute for Astrophysics (INAF) lead the public through constellations, planets, and nebulae, joined by enthusiasts from the Astrofili Bisalta with their telescopes. After dinner, lectures explore the sky as Galileo Galilei saw it in the 17th century, as well as light pollution and the importance of protecting the night sky.

M'illumino di meno and local culture

It is no coincidence that the initiative is part of M'illumino di meno, the day dedicated to energy saving and sustainable lifestyles launched by the Caterpillar program on Rai Radio2. Turning off the lights here means rediscovering the beauty of the starry sky and the value of a preserved alpine environment.

Beyond astronomy, the evening also highlights the identity of Valle Grana: its Occitan culture, mountain trails, and local products, above all the famous Castelmagno PDO cheese, which takes center stage at the refuge dinner. It is a formula that combines science, nature, and gastronomy into a single authentic experience.

Why attend

• Observe the stars in one of Piedmont's darkest skies, guided by INAF astrophysicists.
• Dine at the refuge with traditional Occitan dishes from Valle Grana.
• Attend accessible scientific outreach lectures.
• Experience a sustainable event in the heart of the Cuneo mountains.