11. The Inca built a vast empire without knowledge of the wheel or iron
The largest of the native empires in the Americas before the arrival of the Europeans, the Incas were in many ways baffling. They built massive architecture, including the famed Machu Picchu, though they lacked iron for cutting and shaping stones. They built an intricate system of roads, though they did not use draft animals, nor possess the wheel to facilitate movement and travel. Records were kept through a system of stringed knots, in lieu of a written alphabet. They were tolerant of religious beliefs of the various tribes absorbed into their empire, through conquest or alliance. The empire, which centered in the Peruvian Andes at its beginning, lasted an estimated two and a half centuries.
Exchanges of goods and labor substituted for hard currency, even in the paying of tribute and taxes. The size of the empire and the varying tribes subdued led to a polyglot of languages spoken throughout the Incan lands. At its height, at the time of the arrival of the Conquistadores, the Incan Empire ran down nearly the entire west coast of South America. Its capital, Cusco, contained numerous buildings constructed of huge stones. How they were quarried, transported, and erected remains are mysteries to archaeologists and historical scholars. The Spanish arrived in Inca territory in 1526, Conquistadores led by Francisco Pizzaro.
They found the Inca armed with weapons of wood, stone, and bronze. Another weapon wielded by the Inca was the lasso. The Spanish delivered an ultimatum; conversion to Christianity or war, the Inca chose the latter. Their last stronghold in the formerly vast empire fell to Spain in 1572. The destruction of the Inca Empire, greatly facilitated by the spread of smallpox and other diseases to which they had no immunity, kept many of their secrets from history. Among them were their highly productive farming methods, their construction techniques, and the engineering techniques for building their road systems.