The construction of Tourbillon Castle dates back to the very start of the 14th Century. However, the hill on which it is located had been used since prehistoric times as a defensive vantage point in battles. Made from earth and wood, the primitive defences erected there were temporary structures, which have long since vanished without trace. http://siontourisme.ch/index.php/en/culture/the-4-castles-of-sion/366-tourbillon-13th-century