Chichén Itzá - Cenotes - Valladolid The archaeological site of Chichén Itzá was inscribed on the UNESCO World Heritage List in 1988. On July 7, 2007, it was recognized as one of the New Seven Wonders of the World (with the recognition of millions of voters around the world), being in its time the ceremonial and religious center of the Mayan civilization, standing out among its monuments the Castle of Kukulcán with its 30 meters in height.