Lost Rea: Book IV of the Earth Chronicles

In the sixteenth century, Spanish conquerors came to the New World in search of El Dorado, the fabled city of gold. Instead, they encountered inexplicable phenomena that have puzzled scholars and historians ever since: massive stone edifices constructed in the Earth's most inaccessible regions . . . great monuments forged with impossible skill and unknown tools . . . intricate carvings describing events and places half a world away.