Golden Butterfly of Lerici: Archaeoastronomy in the Gulf of Poets

Hidden among the evocative woods of Monti San Lorenzo, near Lerici in the Gulf of Poets, stands a megalith that offers a one-of-a-kind show every summer. The silhouette of a golden butterfly emerges from the mysterious “tetralithon“, a megalith built with four carved rocks, thanks to the sun’s rays that pass through the monument during the summer solstice.

This unique optical phenomenon, which has been repeating itself for millennia, is not the result of chance but of a human construction aimed, among various hypotheses, at celebrating the transition to the new summer season. The six days around the summer solstice (21 June) offer the clearest vision, but the phenomenon is visible, although slightly distorted, from 25 May to 29 July.

The tetralithon megalith [Photo by Enrico Calzolari] — The tetralithon megalith

The tetralithon megalith during sunset [Photo by Enrico Calzolari] — The tetralithon megalith

Professor Enrico Calzolari, born in Lerici and an expert in archeoastronomy, discovered this megalith and the luminous phenomenon in the nineties. Calzolari argued that this area, anciently inhabited by the Ligurians and Celtic tribes, contains a thousand-year-old energy used by man to celebrate rites and connect with the cosmos:

“In an area that emanates unique energies, we can observe this fascinating mystery that repeats itself every year and takes us back to forms of primitive astronomy, to rituals linked to the cycle of the seasons, to shamanic values, to the cult of fertility.”
(Enrico Calzolari “La farfalla di luce dorata”, edizioni Cinque Terre)

*Another curious effect: after the butterfly disappears, the golden triangle appears! [Photo by Enrico Calzolari*]

Calzolari (1938-2020) believed that men created the tetralithon in the 7th millennium BC. Its purpose has many interpretations – for example, a rite of passage linked to the seasons, transmigration of souls, or a fertility rite – but the emotion of seeing the butterfly come to life with the force of the sun’s rays is unique.

How to reach Lerici’s Golden Butterfly

To reach this megalithic site in the Gulf of Poets, you must take the road from Lerici to Monti San Lorenzo. Once you reach a clearing where you can park your car, follow the signs and proceed on foot along a short path for a few hundred metres. Numerous hiking and biking trails cross the area, offering a complete immersion in the woods of the Caprione Promontory.

hiking trails on monte caprione sentieri

For information on the paths and the possibility of guided tours to Lerici’s Golden Butterfly, you can contact the APS Enrico Calzolari Pro Monte Caprione on Instagram at @apsenricocalzolari or by email at .

The ideal time to arrive on the days around the solstice is around 8pm when the sun’s rays begin to paint the image of the butterfly through the vegetation and rocks. The clarity of the sky and the absence of clouds are crucial to thoroughly enjoying this unique spectacle!

Other megalithic sites: Cinque Terre dolmen and altar stone

Other mysterious megalithic sites nearby can be found along Hiking Path No. 1 of the Cinque Terre Natural Park. On the Monte Grosso hill, near Riomaggiore, there is a prehistoric altar stone with a cup mark and a megalithic monument made up of a small dolmen and an egg-shaped stone divided in half. Cup marks and “egg” stones are distinctive traits found in many ancient sites around the world, their meaning still shrouded in mystery.