As countries go, the United States is over a couple hundred years old now. That's not very old, though, when compared with many other countries around the world. In this fairly young country, where is its oldest city?

Most people would point you south to answer that question. About 40 miles southeast of Jacksonville sits the city of St. Augustine, Florida.

In 1513, Spanish explorer Juan Ponce de Leon discovered Florida on his search for the legendary Fountain of Youth. He landed at St. Augustine, which claims to be the oldest continuously settled city in the United States.

Claimed as a Spanish territory, St. Augustine was officially founded in 1565. That's a full 42 years before the British founded Jamestown, Virginia, and 55 years before the Pilgrims landed at Plymouth Rock in Massachusetts.

Although British forces destroyed most of the original buildings in St. Augustine in the early 1700s, the city's architecture still pays tribute to its Spanish origins. The city's Historic Colonial District still contains dozens of old buildings with balconies that overlook narrow streets.

Before Juan Ponce de Leon ever reached Florida, though, he founded a settlement at Caparra in what is now the United States territory of Puerto Rico. Caparra became the current city of San Juan. Some argue that San Juan should be considered the oldest U.S. settlement.

Of course, both San Juan and St. Augustine were settled by European explorers. But what about the indigenous peoples that lived throughout the lands that would become the United States?

Historians believe the oldest indigenous settlement in the United States might have been the ancient city of Cahokia. Located in Southwestern Illinois between East St. Louis and Collinsville, the modern city of Cahokia is home to the Cahokia Mounds State Historic Site.

Experts think Cahokia may have been settled as many as 3,500 years ago. The first inhabitants of the area were likely members of the indigenous Mississippian culture. Hundreds of years before Europeans arrived, the Mississippians created advanced societies throughout central and eastern North America. The huge earthen mounds created by the Mississippians are preserved today at the Cahokia Mounds site, which is a National Historic Landmark. The site is also the largest prehistoric earthen construction in the United States and one of only 21 World Heritage Sites in the U.S.

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