Gold from Seven Cities

Seven ships filled with gold, silver, and treasures of the Church sail from Hispania to escape invading Moors in the seventh century, going westward where the wind carries them under divine guidance.
The foreigners and natives settle in an area now called Chaco Canyon to establish a religious center and build seven cities of gold and silver that historians and treasure hunters still talk about and seek.
The people, and their cities of gold, disappear without a trace centuries before fortune hunters come seeking the cities and the wealth they contain. Only a select few people remain to oversee the secrets of the ancient people, their treasure, and the plan for using that treasure.