Peru & Machu Picchu
The summit had enough adobe buildings to house 5000 warriors as well as 3 great towers. It took 4 years for 20,000 workers to build Sacsayhuaman. Inca subjects paid taxes with their labor, so a huge workforce was available. It was here that the Inca were defeated when they rebelled after 3 years under the Pizarro brothers. The battle lasted several weeks and thousands died.