In the château entrance, dated 1785, this fascinating device carries the Latin inscription MERIDI A NUM. But what is it exactly? This device reveals itself only once a year—at solar noon on the winter solstice. In that fleeting moment, a beam of sunlight passes through a disc outside the château and strikes the meridian with precision. A great reminder of the 18th century obsession with scientific discovery and new knowledge that was part of the Age of Enlightenment. | Château de Purnon