16. The Carnac stones are NOT remnants of an ancient alien astronomical observatory
The Carnac stones, located near the eponymous village in Brittany, France, are a dense collection of more than 3,000 prehistoric standing stones. Erected by pre-Celtic inhabitants of Brittany sometime between 4500 BCE and 3000 BCE, the stones, each approximately 4 meters high, form the largest known collection of standing stones in the world. Arranged in a number of groups, the main alignment involves 12 rows stretching more than a kilometer in descending order of height and a stone circle at either end.
Whilst local myth claims they are the remains of a Roman legion turned into stone by the wizard Merlin, proponents of ancient astronaut theory assert they were created by alien visitors to serve an alternate purpose, either as Erich von Däniken claimed as an astronomical observatory and landing site for these extraterrestrial tourists or as an elaborate earthquake detector.
Academic opinion is split between two chief possibilities, the first, and less accepted, being that the stones served as a man-made calendar. First proposed by Alexander Thom, this contention suggests the stones operated in some way to inform farmers of harvest seasons and celestial phenomena. The second and more widely recognized theory remains that the stones served a funerary purpose, similar to those of Saint-Michel which predate the site at Carnac, forming part of an enormous necropolis.