While treasure hunters compete for the San José in Colombia and the Atocha in Florida, Andalusian archaeologists map a 17th-century Spanish galleon with 27 intact cannons and evidence of cargo linked to the colonial silver fleet at just 6 meters deep in the Bay of Cádiz.

While treasure hunters compete for famous wrecks like the San José in Colombia and the Atocha in Florida, Andalusian archaeologists map a 17th-century Spanish galleon with 27 intact cannons and evidence of cargo linked to the colonial silver fleet at just 6 meters deep in the Bay of Cádiz, according to a report by Heritage Daily.

The site is approximately 3 nautical miles (about 5.5 km) from the coast. The research is conducted by the Center for Underwater Archaeology linked to the Andalusian Institute of Historical Heritage (IAPH).

Archaeologist Milagros Alzaga García, head of the operation, coordinates identification, recording, and conservation strategy. The focus is on heritage treatment, not commercial recovery.

ARTICLE CONTINUES BELOW

Why Cádiz is a cemetery of 17th-century galleons

The Bay of Cádiz operated as a central port for transatlantic flow for 3 centuries. Cargoes arrived from the Caribbean, New Granada, and the Philippines, were redistributed, and sent to the rest of Europe.

According to studies from the University of Seville, the Carrera de Indias system handled about 17,000 voyages of Spanish galleons between 1500 and 1778.

Silver from Potosí, then in the Viceroyalty of Peru, formed the bulk of the cargo. The annual caravans reached up to 100 ships in military escort.

On the other hand, Cádiz combined 3 risk factors. Intense ship traffic, vulnerability to Atlantic storms, and proximity to English and Dutch piracy routes.

The 3 main attacks occurred in 1587 (Francis Drake), 1596 (Earl of Essex), and 1702 (War of Succession).

In parallel, the catastrophic tornado of 1671 over the Bay of Cádiz is a classic reference in naval literature. The event destroyed at least 30 anchored ships and paved the way for heritage losses that archaeologists are still tracing today.

The numbers of the find in Cádiz

The pace of archaeological work in Cádiz has accumulated discoveries since 2024. According to El Debate, a 400-year-old galleon found in 2024 halted port works at the city’s terminal.

This find was a precursor to the current one.

According to El País, another 16th-century ship, Italian and sunk by Francis Drake’s attack in 1587, was documented by the IAPH in April 2026.

These are 2 finds in 2 years in the same perimeter.

The current site with 27 cannons is at 6 meters deep. The distance of 3 nautical miles from the coast places it in a low-pressure zone for recreational diving but high exposure to sand movement and local currents.

Above all, the presence of 27 cannons is significant material evidence. Common merchant galleons carried 8 to 16 cannons.

Quantities above 20 indicate a military escort vessel of the fleet or a high-value merchant ship with reinforced defense.

Rusty bronze cannon emerges from the sand in the Bay of Cádiz during archaeological survey — One of the 27 cannons documented by the Center for Underwater Archaeology on the 17th-century galleon in Cádiz. Image: IAPH release.

Technical reveal: how the IAPH documents without removing the site

In the background, the IAPH adopts a heritage protection protocol established by UNESCO in 2001. The Convention on the Protection of the Underwater Cultural Heritage recommends keeping sites in place whenever possible, rather than removing them to a museum.

According to the IAPH, the team uses side-scan sonar sweeps, underwater 3D photogrammetry, and bathymetric surveys to map the site without disturbing the material.

The data generates a precise three-dimensional model, millimeter by millimeter.

The system integrates 4 technical layers. The first is geophysical mapping. The second is photogrammetry with compact cameras at various angles.

The third is discrete fragment sampling for chemical analysis. The fourth is continuous erosion monitoring.

On the other hand, the site is vulnerable to 3 concrete threats. Intense maritime traffic from the commercial port, trawling in the region, and unauthorized visits by divers.

The Junta de Andaluzia imposed a 500-meter protection perimeter around the site.

The silver fleet and the central role of Cádiz

The Spanish Carrera de Indias system lasted exactly 278 years. It operated from 1500 to 1778, connecting 7 key ports: Seville, Cádiz, San Juan, Cartagena de Indias, Havana, Veracruz, and Manila via Acapulco.

According to the University of Seville, the silver galleon transported 250 to 600 tons of average capacity.

The typical cargo included silver from Potosí in bars, eight-real coins, Mexican cochineal, indigo, cocoa, and tobacco.

The average annual value of the Seville-Cádiz flow in the 16th and 17th centuries reached 8 million pesos of eight reales. In present value adjusted for historical inflation, this equates to about €2.5 billion annually per voyage on average in the 17th century.

In parallel, Cádiz replaced Seville as the main port of the Carrera in 1717. The Guadalquivir River silted up and prevented larger ships from reaching the interior.

The Casa de Contratación officially moved, consolidating Cádiz as the naval capital.

Aerial view of the Bay of Cádiz with port and coastline contours housing the 17th-century galleon — Bay of Cádiz, the main Atlantic hub of the Spanish Empire between 1500 and 1778. Image: Junta de Andaluzia release.

Human reveal: Milagros Alzaga García and 25 years at the Center for Archaeology

The human face of the operation is archaeologist Milagros Alzaga García, head of the Center for Underwater Archaeology of Andalusia since 2018. Before that, she worked for 18 years as a senior archaeologist at the same institution.

According to an interview published by the Andalusian Institute of Public Administration, Alzaga García has conducted more than 40 underwater archaeology projects on the Andalusian coast.

The research includes 12 sites already mapped and 6 declared Cultural Heritage Sites.

On the other hand, the IAPH technical team consists of about 18 permanent professionals in underwater archaeology. They cover the 836 km of Andalusian coast, of which approximately 12% have archaeological records.

In parallel, the team collaborates with universities in Seville, Cádiz, and Granada. The annual budget of the Junta de Andaluzia for underwater archaeology is €1.8 million.

Each new find adds about 2 to 3 years of documentation work.

Comparison with the 3 most famous shipwrecks of the Spanish Caribbean

The Cádiz galleon differs from the 3 largest shipwrecks in the Spanish circuit. The Nuestra Señora de Atocha, sunk in 1622 off the coast of Florida, was discovered in 1985 with 40 tons of gold and silver.

The current valuation of the cargo exceeds $450 million.

The San José, sunk in 1708 off the Colombian coast during the War of Succession, carries about 11 million pesos of gold and silver to the bottom.

The Smithsonian calls the ship the “Holy Grail of shipwrecks,” with a valuation between $4 and $17 billion.

The Santa Margarita, sister ship of the Atocha, sank in the same 1622 hurricane. Its cargo included 419 silver ingots and about 31 tons of refined silver destined for Seville.

It was partially recovered by Mel Fisher between 1980 and 1992.

Archaeologist divers document submerged structure of Spanish galleon in shallow waters of Cádiz — Team from the Center for Underwater Archaeology documents the galleon site in 3D photogrammetry. Image: IAPH release.

Future reveal: what’s next in the 2027 phase

The next step planned by the IAPH is to complete the 3D photogrammetry of the site by mid-2027. Then comes the phase of chemical analysis of materials and dendrochronology dating of preserved wood.

According to the Junta de Andaluzia, the long-term goal is to classify the site as a permanently protected Cultural Heritage Site.

This status guarantees Spanish federal resources and prevents any port works within 500 meters.

In parallel, there is a plan for a traveling exhibition with smaller recovered pieces and the 3D model of the site. The preliminary schedule foresees a debut in museums in Cádiz, Seville, and Madrid in 2028.

It is worth remembering the coverage of historical events with global impact that helps contextualize the scale of this archaeological discovery.

Location: Bay of Cádiz, Andalusia, Spain
Depth: about 6 meters
Distance from the coast: approximately 3 nautical miles (5.5 km)
Century: XVII (1601-1700)
Documented cannons: 27
Team: Center for Underwater Archaeology of IAPH-Andalusia
Leader: Milagros Alzaga García
Protection perimeter: 500 meters

Detail of 17th-century iron cannon recovered in excavation of the Bay of Cádiz — Detail of cannon recovered from the Cádiz galleon: 27 units documented at the site. Image: IAPH release.

The points that still depend on identification

Despite the progress, 3 fronts still depend on additional research. The positive identification of the ship with its proper name, route, and crew has not been completed.

The possible association with the tornado of 1671 or the War of Succession of 1702 is still a hypothesis.

On the other hand, the exact value of the cargo and the final destination are uncertain. The chemical analysis of silver fragments will indicate the origin in America, whether from Potosí or Zacatecas.

Finally, the state of preservation of the wood in shallow waters requires continuous monitoring by the Junta de Andaluzia.

While treasure hunters compete for the San José in Colombia and the Atocha in Florida, Andalusian archaeologists map a 17th-century Spanish galleon with 27 intact cannons and evidence of cargo linked to the colonial silver fleet at just 6 meters deep in the Bay of Cádiz.

Why Cádiz is a cemetery of 17th-century galleons

The numbers of the find in Cádiz

Technical reveal: how the IAPH documents without removing the site

The silver fleet and the central role of Cádiz

Human reveal: Milagros Alzaga García and 25 years at the Center for Archaeology

Comparison with the 3 most famous shipwrecks of the Spanish Caribbean

Future reveal: what’s next in the 2027 phase

The points that still depend on identification

While an average building in London or New York takes three years to be completed, in China a 26-story tower went up in five days with about 100 workers, and the global modular construction market already moves US$ 95 billion per year.

Australia installs giant concrete structures on the seabed 800 meters from the shore to create an ocean intake for desalination that will draw in saltwater and produce 30 million liters of drinking water per day.

While a traditional school may take several days just to raise walls, in Malawi a 3D-printed school had its structure ready in 18 hours, welcomed children in June, and showed a new solution to the lack of classrooms.

Goodbye traditional washing machine: Panasonic surprises housewives with the NA-G5 featuring four drums, a 13 kg washer and dryer, a 12 kg dryer, independent mini washers, a heat pump, and a 4-in-1 system awarded at the German Design Award.

While cities spend fortunes patching potholes and tons of plastic become waste, the Netherlands transforms over 218,000 recycled cups into a modular bike path that can conceal drainage, cables, and pipes.

Empty beer bottle turns into sand, and the sand turns into concrete: an American city has discovered how to recycle glass locally using a solar-powered truck that crushes five tons of bottles per day in a local circular economy project.

While the US and China compete over who will first deploy a hypersonic aircraft on a commercial route, JAXA tested a 2-meter demonstrator with a hydrogen ramjet engine in 2026 under conditions equivalent to Mach 5 with an external temperature of 1832 degrees Fahrenheit.

Attention: Bolsa Família app will undergo changes and the update will reach 19 million families

While traditional driving schools lose 70% of enrollments, the Brazilian government saves R$ 1.8 billion in 5 months with the free theoretical CNH course on the official app and exempts 1.5 million candidates from the mandatory 45 hours.

While Tesla is still awaiting approval for FSD in China, XPENG deploys the country’s first mass-produced robotaxi unit in Guangzhou, with 3,000 TOPS of computing power and latency under 80 ms without LiDAR.

While traditional driving schools lose up to 70% of enrollments, the official app of the Ministry of Transport connects 172,200 accredited instructors to students via GPS and reduces the cost of the first driver’s license by up to 80%.

While treasure hunters compete for the San José in Colombia and the Atocha in Florida, Andalusian archaeologists map a 17th-century Spanish galleon with 27 intact cannons and evidence of cargo linked to the colonial silver fleet at just 6 meters deep in the Bay of Cádiz.

Why Cádiz is a cemetery of 17th-century galleons

The numbers of the find in Cádiz

Technical reveal: how the IAPH documents without removing the site

The silver fleet and the central role of Cádiz

Human reveal: Milagros Alzaga García and 25 years at the Center for Archaeology

Comparison with the 3 most famous shipwrecks of the Spanish Caribbean

Future reveal: what’s next in the 2027 phase

The points that still depend on identification

While an average building in London or New York takes three years to be completed, in China a 26-story tower went up in five days with about 100 workers, and the global modular construction market already moves US$ 95 billion per year.

Australia installs giant concrete structures on the seabed 800 meters from the shore to create an ocean intake for desalination that will draw in saltwater and produce 30 million liters of drinking water per day.

While a traditional school may take several days just to raise walls, in Malawi a 3D-printed school had its structure ready in 18 hours, welcomed children in June, and showed a new solution to the lack of classrooms.

Goodbye traditional washing machine: Panasonic surprises housewives with the NA-G5 featuring four drums, a 13 kg washer and dryer, a 12 kg dryer, independent mini washers, a heat pump, and a 4-in-1 system awarded at the German Design Award.

While cities spend fortunes patching potholes and tons of plastic become waste, the Netherlands transforms over 218,000 recycled cups into a modular bike path that can conceal drainage, cables, and pipes.

Empty beer bottle turns into sand, and the sand turns into concrete: an American city has discovered how to recycle glass locally using a solar-powered truck that crushes five tons of bottles per day in a local circular economy project.

While the US and China compete over who will first deploy a hypersonic aircraft on a commercial route, JAXA tested a 2-meter demonstrator with a hydrogen ramjet engine in 2026 under conditions equivalent to Mach 5 with an external temperature of 1832 degrees Fahrenheit.

A 390-ton transformer traveled 270 kilometers in Sweden during a nighttime operation with special trucks, reinforced bridges, a road lowered by 400 mm, and railway crossings to deliver energy to one of the country’s largest wind power hubs.

AI-powered cameras start fining drivers without seatbelts and using cell phones in São Paulo and Rio de Janeiro.

Port of Paranaguá receives Star Norge, a sustainable ship from Norway, with 14,200 tons of cellulose

With 300 tons and a journey of more than 800 km, a giant transformer leaves Minas Gerais, crosses roads in a special operation, and arrives in the interior of São Paulo to integrate the hidden structure that carries energy underground in Brazil.

While the US and China compete over who will first deploy a hypersonic aircraft on a commercial route, JAXA tested a 2-meter demonstrator with a hydrogen ramjet engine in 2026 under conditions equivalent to Mach 5 with an external temperature of 1832 degrees Fahrenheit.

Attention: Bolsa Família app will undergo changes and the update will reach 19 million families

While traditional driving schools lose 70% of enrollments, the Brazilian government saves R$ 1.8 billion in 5 months with the free theoretical CNH course on the official app and exempts 1.5 million candidates from the mandatory 45 hours.

While Tesla is still awaiting approval for FSD in China, XPENG deploys the country’s first mass-produced robotaxi unit in Guangzhou, with 3,000 TOPS of computing power and latency under 80 ms without LiDAR.

While traditional driving schools lose up to 70% of enrollments, the official app of the Ministry of Transport connects 172,200 accredited instructors to students via GPS and reduces the cost of the first driver’s license by up to 80%.