High in the Bolivian Andes sits a 131-ton block of red sandstone with perfectly flat faces and crisp 90-degree interior angles, cut around 1,400 years ago with tools archaeologists still cannot identify. It is one of the ancient world's ultimate mysteries.

This deep dive explores the real human history of Pumapunku, drawing on field reports from architectural historians and climate studies of the ancient Andes. We unpack the staggering engineering of the Tiwanaku civilization and dismantle the pseudoscience that robs indigenous people of their achievement.

• How thousands of laborers moved a 131-ton stone 10 kilometers, and hauled andesite 90 kilometers across Lake Titicaca on reed boats
• Stella Nair's experiment spending 40 hours failing to replicate a single eight-inch carving with indigenous stone tools
• The copper ...