12-Angled Stone Inca Wall
"The Incas were master architects, masons, and stone cutters. They were known to fit carved stones so close together that the mortar was almost invisible. Blocks of stone had to be cut, ground, and polished until the outer surfaces locked perfectly. Today, it is still uncertain how the Incas cut stone. Most buildings required vasts amounts of labor, and the Inca had no wheels, cranes, or lifting devices."