The long-lost city of Etzanoa, the second biggest Native American settlement in the United States, could have been sitting near Arkansas City, Kansas, all this time.

According to the Kansas City Star, it was a high school student who stumbled on the find that Wichita State University's Donald Blakeslee says is evidence of a massive city at the confluence of the Walnut and Arkansas Rivers.

What the researchers have found point to the previous existence of a massive town that was the stuff of Wichita legend. It extends across thousands of acres along the pair of rivers. Artifacts found on the site further support the site's history as Etzanoa: a half-inch iron cannon ball and a water shrine carved on a limestone boulder.

In 1601, Juan de Oñate, conquistador and founding governor of New Mexico, embarked on an expedition in search of a fabled "city of gold," a report from Archaeological Conservancy revealed. The exploration led him and his men to discover many notable sights, particularly a massive riverside city they called Etzanoa that they stumbled upon during a battle.

Years after their expedition, the soldiers regaled official stories of the vast Etzanoa that featured thousands of thatched-roof buildings that stretched miles long. The explorers believed that around 20,000 people lived in the settlement.

"The Spaniards were amazed by the size of Etzanoa," Blakeslee said. "They counted 2,000 houses that could hold 10 people each. They said it would take two or three days to walk through it all."

But despite its historical significance, the location of the Etzanoa has remained a mystery for around 400 years. Scholars have even dismissed Oñate's stories as the exaggerations of a conquistador -- until now.

"We always knew we once had a whole bunch of Indians living around here, because we had found way too many artifacts to think otherwise," Jay Warren, an Arkansas City council member, said. "But we had no idea until Dr. Blakeslee came along about how big it was."