An international team of archaeologists has found a shipwreck that may be connected to one of the most important naval battles in Latin American history.

The vessel, a Spanish warship built in the early 18th century, may have been intentionally sunk in 1741 during the Battle of Cartagena de Indias, an upset Spanish victory during the War of Jenkins’ Ear, a battle with Great Britain for economic control of the Caribbean. The battle has long been a cultural touchstone in Colombia, which has celebrated the valiant Spanish defense.

Found in some 16 feet (5 meters) of water off the coast of Cartagena, Colombia, the ship’s preservation is remarkable. Large portions of the ship’s bottom are mostly intact, its wooden beams almost perfectly protected from looters and undersea life by layers of sediment.

The vessel's exposed timbers, which have been scanned and modeled in 3D, offer researchers a unique, unrivaled opportunity to study 18th-century shipbuilding.

“It’s an incredibly exciting find, especially if it is what they think it is,” says Jennifer McKinnon, an underwater archaeologist at East Carolina University who isn’t involved with the excavation. “Old World, Spain-built vessels in the New World are rather rare.”

The find also marks an important milestone for Colombian archaeologists, who are taking unprecedented steps to study and preserve the site.

“This discovery is very important, but its cultural significance is much higher,” says Carlos del Cairo, an underwater archaeologist and head of Colombia’s Fundación Terra Firme, which is leading the excavation. “It’s [a] symbol of heroism, of ‘Cartagena the Heroic,’ that defended itself against the British to the last.”

Exclusive Video: Sunken Ship Revealed After 274 Years A shipwreck recently discovered near Cartagena, Colombia, could be one of several Spanish ships intentionally sunk in 1741 to block a British invasion.

An Unexpected Victory

In the 1700s, Cartagena—now Colombia’s fifth-largest city—was a slave port and strategically crucial outpost for Spain’s Caribbean naval presence. The fortified town sat at a junction of ocean currents and trade winds, allowing Spanish ships to dominate the region’s trade routes.

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After Great Britain declared war on Spain in 1739, Cartagena quickly became the British forces’ top target. Admiral Edward Vernon soon embarked with what was then the largest transatlantic amphibious fleet ever assembled: a massive train eventually totaling some 150 ships, carrying 8,000 British soldiers and 4,000 reinforcements from the American colonies, the largest contingent the colonies ever had sent from the mainland.

“It started off in Britain with the idea that this would be an easy victory,” says Richard Harding, a naval historian from the University of Westminster.

But taking Cartagena would prove more vexing than Vernon ever expected, in large part because of Blas de Lezo, the Spanish general in charge of the town’s defenses.

A living legend among Spanish sailors, Lezo—nicknamed Mediohombre, or “Half Man”—literally had given life and limb for his country. When Lezo and Vernon first faced each other in battle in 1704, a cannonball maimed Lezo’s left leg, which had to be amputated. Two years later, shrapnel claimed his left eye, and not long thereafter, a musket shot took his right hand and forearm.

By the time the British arrived in Cartagena in March 1741, Lezo was David to Vernon’s Goliath, charged with defending the city with only six ships. In fact, the British had already minted medals commemorating Lezo’s defeat.

Lezo decided to sink his ships at the narrow entrances to Cartagena’s harbor to impede the incoming British. The barricade didn’t hold forever; the British eventually got into the harbor and even tried to use one of Lezo’s ships as a makeshift battering ram.

But crucially, the sunken ships and Cartagena’s formidable fortifications bought Lezo time. Vernon’s men soon began to fall ill with yellow fever and other tropical diseases, a situation only worsened by the British fleet’s meager supplies.

Several months later, Vernon was forced to abandon his siege of Cartagena, after a land assault was repulsed by Spanish militias under Lezo’s command. At least 5,000 British troops died, many from illness. Fewer than one out of every six American colonists who joined the British forces returned alive.

“It was rather a bit of a debacle,” says Harding. “I think it surprised the British tremendously.”

The unexpected victory not only cemented Spanish dominance in the Caribbean until the Seven Years’ War; the heroism of Blas de Lezo and his forces also became celebrated and central to Colombia’s cultural heritage.

“Despite his physical conditions, Blas de Lezo stood his ground until the bitter end,” says Cairo, making him “one of these characters who has enormous cultural and historical value, even today.”

The battle also glancingly affected U.S. history. Lawrence Washington, one of the surviving colonists, later named his family’s estate after his commanding officer, giving rise to Mount Vernon—the homestead of Lawrence’s more famous half-brother, George.

View Images A statue of Blas de Lezo, the Spanish general who oversaw Cartagena’s defenses, stands near San Felipe de Barajas, one of the town’s colonial forts. One of Lezo’s many nicknames was Almirante Patapalo—Admiral Pegleg. Photograph by O. Louis Mazzatenta, Nat Geo Image Collection

An Accidental Find

Cairo and his colleagues didn’t intend to find one of Lezo’s fabled sunken warships. In 2014, the Colombian Institute of Anthropology and History (ICANH) commissioned a routine survey of the area in preparation for a dredging project. Sonar and magnetometer sweeps detected anomalies on the seafloor within the Bocachica (“small mouth”) entrance to the harbor, which turned out to be the ship.

In addition to the vessel’s wooden structure, dives to the site have yielded fragments of ceramic, metal, glass, and ballast, all of which are consistent with an 18th-century ship of Spanish make. Though more analysis is necessary to verify the ship’s association with the 1741 battle, the site’s alignment with historical maps—and signs that the ship may have burned before sinking—suggest that the vessel may be the San Felipe, among the largest of the ships that Lezo sunk.

“It’s like a puzzle [with] many clues,” says Cairo.

The site’s ongoing management signifies a landmark collaboration between the Fundación Terra Firme and a vast array of Colombian government institutions, all of which are working toward an eventual plan to excavate and protect the shipwreck.

“It’s perhaps the first site that’s been developed in Colombia with these characteristics,” says Ernesto Montenegro, an underwater archaeologist and the director of ICANH. “This is a step forward for Colombian archaeology.”

The unprecedented effort is striking to Cairo’s colleagues, who hail from across Latin America.