Constructing a ten-mile stone wall through the middle of a massive lake is an engineering nightmare. The Nezahualcoyotl Dike, built to protect Tenochtitlan from both catastrophic flooding and salt contamination, faced immense horizontal pressure from the water and deep vertical instability from the soft, saturated lakebed. Traditional stone masonry would simply sink into the mud under its own weight. Aztec engineers bypassed this catastrophic failure by completely reinventing their foundation strategy. They drove thousands of heavy wooden pilings deep into the muddy floor, creating a friction-based anchoring system rather than relying on solid bedrock. Between these wooden teeth, they packed alternating layers of porous volcanic rock and highly impermeable clay, effectively building a flexible, buoyant barrier capable of absorbing seismic shocks and shifting water levels without cracking. Deconstruct the geotechnical brilliance of the Mexica. Grasp the friction mechanics and soil stabilization techniques required to build a massive, enduring dam on top of a liquid foundation.