Treasure in the Jungle Mist by Bill J. Harrison

Beneath the misty canopy of the Mexican jungles, are the decaying ruins of a once-noble civilization called the Maya. During their glory days, the Mayans built great cities, adorning them with gleaming gold, turquoise, silver and dazzling precious gems. The ancient Mayans are long dead, their cities buried beneath rotting jungle debris – but their priceless treasures remain.