After a daylong slog through the suffocating Guatemalan jungle, we emerged before a soaring pyramid in the ghostly ruins of El Tintal, our first stop in the forested realm of the Serpent King.

A slight breeze stirred the air, offering a respite from the heat. We climbed the pyramid and watched the forest swallow the sun. Earthen mounds entombing cities lost to time lay scattered below. And we were heading for El Mirador, the grandest city of them all, only now beginning to reveal its secrets.