It strains the imagination to think how the Andean Indians were able to transport stones weighing 100 tons or more over ten miles of mountainous terrain from their distant quarry, then fit them perfectly into place along the fortification. (One 28-foot-high monster weighs in excess of 700,000 pounds.) Archaeologists, still struggling to explain away this unfathomable feat, have attempted to duplicate a small fraction of Viracocha’s legacy by transporting one medium-sized boulder from a distant quarry using advanced engineering principles and a small army of volunteers. To this day, every undertaking has failed miserably.

We know the fortress of Sacsayhuaman was erected to protect its inhabitants from hostile forces. The true purpose behind the design of Viracocha’s other structure, the ancient Andean city of Tiahuanaco, still remains a mystery.

Situated 12,500 feet above the Pacific in the Andean Mountains of Bolivia, the ruins of Tiahuanaco rest on the ancient shoreline of Lake Titicaca, the highest body of navigable water in the world. After examining the impossible engineering feats at Sacsayhuaman, I would have sworn that nothing henceforth would surprise me. Despite this, the site of Tiahuanaco was simply overwhelming. The ground plan of this ancient city consists of three limestone temples and four other structures, all set on a series of raised platforms and sunken rectangles. As in Sacsayhuaman, the majority of construction consists of impossibly large boulders fitted together perfectly.

But there is clearly more to Tiahuanaco than meets the eye. A hidden agenda is present here—an agenda that may relate to the very salvation of our species.

Dominating the city is the remains of the Akapana, a step pyramid whose four directionally oriented sides each measure 690 feet. The purpose of Akapana, alas, must remain a mystery as the invading Spanish used the structure as a quarry, robbing the temple of 90 percent of its facing.

The most wondrous structure in Tiahuanaco is the Gate of the Sun, a single, massive block of stone weighing 100 tons. This mammoth work of art stands in the northwest corner of the complex like some prehistoric Arc de Triomphe. Somehow, its creator managed to transport this enormous block of stone from a quarry miles away, carve out a perfect portal of a door using God knows what kind of tool, then vertically align the piece into place.

Giant pillars proliferate in the city. At the center of a sunken, rectangular open-air pit stands a seven-foot-tall red rock carving of Viracocha himself. The elongated skull is present, as well as the prominent forehead, thin straight nose, and the beard-covered jawline. The arms and hands are folded. A final feature worth mentioning: Rising along either side of the wise man’s robe are two serpents, similar to those depicted throughout Mesoamerica.