The Inca Empire was a powerful pre-Columbian civilization with a massive empire stretching for thousands of miles, covering almost the entire west coast of South America. They were ahead of their time with government, infrastructure, agriculture, and science. Machu Picchu is probably their most famous achievement, but there is much more to the Inca Empire than a temple on a mountain. Here are six incredible facts about the Inca Empire.

They had a massive empire

Aerial view of Machu Picchu architecture and landscape with mountains in background
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The Incas didn’t have a writing system, so it’s hard to determine when the empire officially started. It reached its prime between 1400 and 1533 CE. The Incas were very smart and had built a strong central government and a massive military that was sustained on taxes. By 1471, the empire stretched for more than 3,400 miles, covering most of the west coast of South America. It was the largest empire in the world at the time, including European nations, and consisted of 10 million people ruled by 40,000 Incas.

They built an incredible network of roads

Dusty dirt road with mountains and sign indicating llama crossing in the region
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Although they never had access to the wheel, the Incas built a massive network of roads that stretched for more than 25,000 miles. These roads were primarily used for trade, military operations, and quickly sending messages across the massive empire. Llamas were the Incas' most important asset. They were used as pack animals to carry goods and supplies.

Every couple of miles were small stations or larger rest stops so that travelers could take a break or spend the night during longer voyages. Much of the road and rest stations still exist and are listed as a UNESCO World Heritage Site.

They developed their own postal system

Traditional Incan rope bridge used by Casqui creating a path between two rocky outcroppings
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Because their empire was so massive, the Incas had to come up with a way to quickly and efficiently spread messages throughout the land. Chasqui were the mailmen of the Inca Empire. They were trained runners that could travel up to 250 miles per day to deliver a message. Chasqui would work in pairs: one would always stay awake in case an important message needed to be delivered.

Because there was no written language, the messenger had to remember what they were supposed to deliver. They used the extensive road network and specialized rope bridges to quickly move through the empire.

Machu Picchu was never finished

Aerial view of Machu Picchu interior, showing stone architecture and ancient walls
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Machu Picchu was built in the late 1400s and was an engineering marvel even by today’s standards. The citadel was built high up in the Andes Mountains, 7,800 feet above sea level, which is 2,000 feet higher than the tallest mountain on the East Coast of the U.S. Machu Picchu consists of over 200 buildings carefully built into the landscape.

Unfortunately, the Incas never got the chance to finish it. When the Spanish conquistadors landed in South America, disease wiped out most of the indigenous population long before the Europeans’ weapons could. Machu Picchu was abandoned around 1533. The site is so hard to get to, it wasn’t re-discovered by modern researchers until almost 400 years later in 1911. Today, the ruins are a protected UNSECO World Heritage Site and open to visitors.

A central government collected taxes

Traditional Incan statues representing the arrival of the first Incan civilization
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The Inca had a strong centralized government and regularly collected taxes from citizens. Because money didn’t exist, taxes were collected in the form of food, goods, and even services. They performed annual censuses to keep track of the population and calculate taxes for a given area.

Foodstuffs were stored in government-owned warehouses to feed the army and to help in times of famine. Those who were not farmers or manufacturers could offer labor in lieu of physical taxes. These workers helped with state-run projects like building roads.

They had a unique system of record-keeping

Incan quipu hanging on wall with multi-colored ropes and knots
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While there may have been no formal writing system, the Incas did have an ingenious way to record information. Quipu are complex series of knots tied into a rope or several ropes that indicate numbers, dates, and statistics. Some researchers even claim they can record stories. Some of the larger quipu had up to 1,500 strings!

The location of a knot on the string signifies a decimal position and different knots stood for different values. If you’re nice and confused, that’s okay. So were most people. Quipu masters called “quipucamayos” were in charge of creating and decoding quipus; the average person couldn’t read them.

The strings were small and easy to transport, perfect for the chasqui to carry around. Accurate records could be delivered across the empire without having to rely on memory, which is great when it comes to complicated numbers. Many quipu still exist today and provide detailed information about Inca life and the empire in general.