Around four centuries before the arrival of Columbus to the American continent, the Native Indians of Illinois erected a city that came to support a population of more than 20,000 inhabitants. But not only did they create a sophisticated city, for some reason they built more than a hundred mysterious earthen Pyramids, which, until this day, remain a profound enigma, as well as the general history of the site and its inhabitants.

Scholars consider Cahokia as one of the most significant and most influential ancient settlements in the Mississippian culture that developed and built massive structures five hundred years before Europeans came to the New Continent.

The original name of this ancient city is unknown. The name Cahokia is borrowed from a tribe that lived nearby in the 1600’s.

Cahokia is an ancient settlement with a history that is more profound than we currently are willing to acknowledge.

Washington University’s John Kelly, a longtime stalwart of Cahokian archaeology, sums up the present understanding of Cahokia nicely: “People aren’t sure what it is.”

The first man to write about this ancient city was Henry Brackenridge, a lawyer and amateur historian who noted he was left amazed by what he had seen in 1811:

“I was struck with a degree of astonishment, not unlike that which is experienced in contemplating the Egyptian pyramids. What a stupendous pile of earth! To heap up such a mass must have required years, and the labors of thousands.”

The city, its monuments, and cultures are of great value.

Experts believe that Cahokia was the apogee and may have even been the origin of what scholars refer to as the Mississippian culture which spread across the American Midwest and Southeast starting before A.D. 1000 and peaking around the 13th century.

The building process of the city is another mystery. Researchers say that everywhere they dug, they found something of value, houses, buildings, monuments. The discoveries made at Cahokia indicate that it was a massive city, which, mysteriously, was built in an extremely brief span of time.

In other words, researchers say that it seems as if the entire city ‘sprang to life almost overnight around 1050’.

People from all over the area started moving to Cahokia which allowed the creation of complex infrastructure. The Cahokians built MASSIVE mounds—earthen Pyramids, a playa with the size of 45 football fields and different ceremonial and religious monuments.

To get an idea of how big the Cahokian earthen Pyramids were if you climb on top of Monks Mound, composed of 156 steps, you’d find yourself atop a structure that is larger at its base than the Great Pyramid of Giza. Now imagine the amount of work that needed to be done to create something like this around 1050.

The base circumference of Monks Mound is larger than the Pyramid of the Sun at Teotihuacan. It is believed that the inhabitants of Cahokia began building it around 900–950 CE, and was completed around 1100 CE.

At its peak around 1100, the city of Cahokia covered more than five square miles and was made up of 120 earthen pyramids. The inhabitants of Cahokia were skilled farmers, traders, and hunters, but they were also excellent urban planners and used astronomical alignments—like many other cultures in the American Continent—to build a small metropolis which was more extensive than many European cities during that tie.

The Cahokians did not leave behind a written language; we don’t know what they called themselves, where they came from, why they build these massive earthen Pyramids, why so many of them, and why they disappeared.

In fact, by the time Columbus got to the Americas, the city was already a ghost town. Experts only know that the city came into existence during a favorable climate phase and began shrinking around the time the climate became cooler, drier, and less predictable.