Thousands of years before the advent of the great classical Maya and Aztec civilizations, an unknown megalithic culture occupied much of Mexico and Central America. In this new episode I interview researcher, author and founder of the ARX project Marco Vigato regarding the lost megalithic cultures of Mexico and the many megalithic mysteries of ancient Mexico. Marco takes on a journey inside the subterranean underworld of Mexico where an extensive network of subterranean chambers have recently been discovered under the archaeological site of Mitla. According to the Zapotecs, these passageways were considered to be an entrance to the underworld. Next we will discuss the huge precision megaliths that were recently discovered in Mexico that look eerily similar to the blocks seen in Bolivia at Tiwanaku.