The islands’ most alluring residents have inhabited the area for nearly 500 years.

The Outer Banks are one of the South’s greatest treasures. The 200-mile stretch of skinny barrier islands off the coast of North Carolina are known for their secluded feel, the small communities that inhabit the islands, beautiful beaches, and of course, the wild horses. Several herds of wild horses—totaling around 400 in total—live throughout the barrier islands and have become a sought-after tourist attraction in their own right. They can be seen strolling along the beaches and wooded areas near Cape Lookout, Beaufort, Ocracoke, and Corolla. Part of the allure of the wild horses is that they’ve lived there for nearly 500 years—longer than any human residents—and have survived hurricanes and human settlers alike. Another part of their allure is the mystery of their presence in the first place: Just how did a herd of wild horses end up on these isolated islands?

The exact origins of the horses that still live in the Outer Banks aren’t entirely known, but we have a pretty good idea. As you may remember from middle school history class, despite our close connection to the animals and the important role they’ve played in United States history, the horses we know aren’t native to North America at all. They were brought over by Spanish explorers during the Colonial era, which is the case for the horses in the Outer Banks as well. And while the herds are technically wild now, they’re descendants of domesticated horses that were brought to the area sometime in the 1500s and left behind—either by choice or by accident.

Legend has it that the mustangs were survivors of Spanish shipwrecks off the coast of North Carolina. Ships participating in transatlantic trade often followed routes that took them very close to what is now the Outer Banks, but many ships fell victim to the hidden shoals and unexpectedly shallow waters—so much so that the area became known as the Graveyard of the Atlantic. At least eight Spanish shipwrecks have been discovered in the area, dating back to the mid-1500s, and any horses on board would have been close enough to swim to shore.

It’s more likely, however, that the horses are the descendants of Spanish mustangs that were left behind by settlers of the area. Two prominent explorers—a Spaniard named Lucas Vasquez de Allyon and an Englishman named Richard Greenville—both have records of being in the area at different times, both with livestock in their possession. Allyon was attempting to settle areas along the coastline, but the Spaniards’ intrusion led to conflicts with local Native Americans, and there are records that show the settlers were forced to flee, leaving their horses behind. Greenville was an English commander who regularly captained British ships carrying traded goods (including Spanish mustangs) between the West Indies, early/fledging English colonies in Virginia, and Great Britain. Records show a ship in Greenville’s fleet in the 1580s was caught in the infamous shallow waters near the Outer Banks and wrecked, leaving the horses onboard to swim to shore.

Whatever their origin, the wild horses that have made the Outer Banks home are a true treasure, protected by the National Park Service, the state of North Carolina, and private funds and sanctuaries that ensure they will remain just that for generations to come.