Archaeologists discovered the submerged remains of the Fort of San Matías, once a protector against pirates and European naval assaults, beneath the waters of Cartagena Bay, Colombia. A team of experts from the Underwater Cultural Heritage Research Group of the General Maritime Directorate (Dimar) identified the fort.
Using three-dimensional acoustic sonar technology, the team mapped the sea floor and uncovered unexpected anomalies. They found that the structure preserved much of its original shape—a perfect square of 82 meters on each side, with walls that still defied the passage of time, according to El Tiempo. The submerged fortification lies at a depth of six meters below the surface of Bocagrande Bay.
Three researchers—Richard Guzmán Martínez, Diana Quintana Saavedra, and Carlos Alberto Andrade Amaya—used the technology to venture into the seabed off Bocagrande. The team aimed to deepen their knowledge about the underwater breakwater known as La Escollera, which has permanently closed navigation through Bocagrande since the 19th century.
Oceanographer Carlos Andrade explained that the underwater structure was better preserved than expected. "Erosion has been minimal. We can say that San Matías is still standing, although it no longer watches over pirate ships, but over fish and corals," said Andrade.
Records indicate that the Fort of San Matías was abandoned following a Royal Decree in 1626, which ordered its dismantling due to its deteriorated state after years of storms and neglect, according to Semana. By the end of the 16th century, the fortification was in ruins and had lost its functionality of guarding the city from invasions, leading to its eventual submersion and loss from maps.
Constructed by order of Governor Pedro de Acuña in 1567 on a sandbank at the entrance to the Bay of Cartagena, the Fort of San Matías served as a protective shield for the city against pirate and privateer attacks, reported Semana. Its strategic location at the mouth of Bocagrande Bay underscored the importance of the territory, which was repeatedly besieged by English, French, and Dutch naval forces, according to thecitypaperbogota.com.
Ancient maps revealed that Bocagrande was not always the peninsula it is today, as reported by El Tiempo. In the 16th century, Bocagrande was an open channel that connected the bay with the open sea, making Cartagena vulnerable not only to human siege but also to the harshness of the sea.
To prevent future invasions, the Spanish decided to close the channel, first with stones and then with the Escollera de Bocagrande, a submerged wall that sealed the access definitively. It was at this barrier that the researchers found the ruins of the fort.
Captain Saúl Esteban Vallejo Quintero, responsible for Underwater Cultural Heritage at the General Maritime Directorate, explained that an interdisciplinary group worked on this project for several months, reported Semana. "With the implementation of different methodologies and with an interdisciplinary team composed of hydrographers, oceanographers, archaeologists, anthropologists, historians, and divers of the National Navy, it was possible to create this team of more than twenty researchers and a dozen field outings by the General Maritime Directorate to make this important discovery," said Vallejo Quintero, according to Semana.
Other colonial structures, such as the Fort of San Luis in Bocachica and the Santángel Batteries, are believed to lie submerged, with their precise locations still shrouded in mystery.
The Fort of San Matías's location within a busy urban bay makes it vulnerable to damage from human activity, emphasizing the need for monitoring and protection of Cartagena's underwater cultural resources.
By 1626, the fortification was no longer an impregnable bastion but a giant wounded by time, according to El Tiempo. After its dismantling, only vague references to the Fort of San Matías remained in colonial maps and chronicles.
The article was written with the assistance of a news analysis system.