Valdivian Fort System

The Fort System of Valdivia are a series of Spanish colonial fortifications at Corral Bay, Valdivia and Cruces River established to protect the city of Valdivia, in southern Chile. During the period of Spanish rule (1552–1820), it was one of the biggest systems of fortification in the Americas.[1] It was also a major supply source for Spanish ships that crossed the Strait of Magellan.


The main fort in Corral
General view of the fort in Corral
Map of Corral Bay and the location of the coastal defences. The four largest forts are marked with red
Niebla Fort's former headquarter (now a museum), during a representation of the capture of Valdivia

Valdivia was founded in 1552 by the Spanish conquistador Pedro de Valdivia. Some years later in 1598 the Spaniards suffered several reversals in the War of Arauco, and the defenceless city was abandoned. In 1643 the Dutch arrived at the ruins and settled in the zone, planning to use Valdivia as a base for attacks on the Spanish empire. After some conflicts with the Mapuche Indians of the zone, the Dutch had to leave Valdivia.

It was then when Pedro Álvarez de Toledo y Leiva, Marquis of Mancera ordered the re-population of Valdivia and the construction of several forts. The main forts were built at Corral Bay, but some other forts were built to protect the city from the Mapuches. Then the city came to be called The key of the south sea and Gibraltar of the Pacific.

The Spanish Crown early perceived the strategic nature of Ghilets southernmost region which, through the Magallanes Strait and Cape Horn, was an intermediate point for navigation from Europe to the American Pacific coast. From the end of the 16th century, the construction of fortifications in this area became a high priority due to the frequent transit of French, English and Dutch ships and, particularly, to pirates' raids.

To the destruction in the Chilean and Peruvian coast caused by Francis Drake in 1578, were added expeditions like that of the Dutch Hendrik Brouwer, who, in 1643, occupied for a time the littoral adjacent to the mouth of the Valdivia river, with the purpose of challenging from there the Spanish might. These incidents led the Spanish authorities to undertake the construction of powerful defensive facilities in Valdivia, Valparaiso and Chiloé. Valdivia, the oldest of the three, would become, along with El Callao, the most important defensive complex of the American South Pacific coast.

Both are exceptional samples of the Hispanic-American school on fortifications. The reason for this effort and the resources invested in Valdivia stem from the need of defending Peru, colony which along with Mexico constituted the main source of wealth of the Spanish Crown. In 1645, the Viceroy of Peru, Antonio de Toledo, Marquis of Mancera, started the execution of a patiently designed defensive plan. One of its fundamental aspects was the dispatch of a great Armada to refound the city of Valdivia -devastated as a consequence of the 1598 native revolt-, and the raising of fortifications on the coast. The contingent in charge of the mission was organized in Peru, and it astounded its contemporaries by its magnitude. Seventeen ships were gathered, equipped with an amount never seen before of building materials and supplies.

The original fortification plan was based on using the exceptional defensive qualities of the Corral Bay, at the mouth of the Valdivia River. The project contemplated the building of four basic fortresses which, in case of attack, would jointly operate with its cross-fire. In the disposition of these four central points and in the design of these bastions, topographical, geographical and environmental factors were fitted together: sea currents, ground unevenness, prevailing winds, etc. Although with the passage of time the installations grew with regard to the number of batteries, and the role of the four basic fortresses changed, the original scheme remained unaltered, with four sites retaining their leading part: the Mancera island, Corral, Amargos and Niebla.

The main bastion of this defensive complex was the Constantino island, later called Mancera. The island is located in the middie of the bay into which the Valdivia River flows, and there the San Pedro de Alcantara Castle was built according to the project designed by the Navy chief engineer, Constantino Vasconcelos. The castle, made of stone, was armed with fifteen pieces of artillery, and had a moat and two turrets. Inside it, among other installations, there was a church and two convents: one Franciscan, and the other Augustinian. At the so-called Punta de Amargos, on the southern side of the Valdivia river mouth, the San Luis de Alba Castle was built, entirely of stone. It had up to eleven pieces of artillery, which due to its strategic position, couid batter down the anchorage of enemy ships. The castle was isolated from it surroundings by a moat, crossed by a draw-bridge. Aside from the quarters and the commander's house, there was a chapel inside the castle. At the end of the 18th century, the bastion was reinforced, and some buildings in brick were added to it. Nowadays, none of the inner constructions of the complex remain standing, yet the basic stone structure with its artillery pieces has survived and has been restored.

The Fort of Niebla stands up on the northern side of the Valdivia river mouth. It was built on a Cancagua stone slope about 30 meters high, dominating the entire bay and open sea. Its very original design adapts itself well to the site geography. The Fort of Corral, to the south of the said mouth, was fully remodeled in the second half of the 18th century. It consists in a long battery facing the sea: 24 cannons standing on a solid stone wall. Both the inner constructions and the defenses towards inland have vanished.

In the second half of the 18th century, a thorough plan was carried forward for restoring and improving the fortresses. The engineers José Birt and Juan Garland were commissioned for the task. The defensive complex of Valdivia reached the point of having 17 bastions, with surveillance installations, castles, fortresses and batteries. This complex would exert during the Colony a thoroughly efficacious deterrent effect, since, in fact, it frustrated the raids of the rival powers.

Paradoxically, those who took these defenses to pieces weren't the European enemies, but the independentist patriots. At the time of Chilean independence Valdivia remained a Spanish stronghold, and was perceived as threat to Chile's independence by Lord Cochrane, admiral of the Chilean navy who captured the forts in 1820 without facing the batteries by using a surprise land assault. Valdivia surrendered when the news about the fall of Corral Fort came.

The four largest forts in this system were the forts in Corral Bay that controlled the entry to Valdivia River, thus Valdivia. Other fortifications were built to defend the city from land attacks (mostly from indigenous Huilliches).

  • 1 - Fuerte Aguada del Inglés
  • 2 - Fuerte de San Carlos
  • 3 - Batería del Barro
  • 4 - Castillo de San Luís de Alba de Amargos
  • 5 - Batería y Reducto de Chorocamayo
  • 6 - Castillo de San Sebastián de la Cruz Fort (Corral Fort)
San Sebastián de la Cruz Fort in Corral at the southern side of Corral Bay was the headquarters of the coastal defences. It was built in 1645 by order of the viceroy Pedro Álvarez de Toledo y Leiva.
  • 7 - Castillo de San Pedro de Alcántara (Isla Mancera Fort)
The fort of Mancera Island lies between Niebla and Corral. Due to its strategical location, several times the city of Valdivia was proposed to be moved into the small Mancera Island - a proposal Valdivias citizens opposed.
  • 8 - Batería del Carbonero
  • 9 - Batería del Piojo
  • 10 - Castillo de la Pura y Limpia Concepción de Monfort de Lemus (Niebla Fort)
The fort in Niebla faces Corral Fort and lies at the northern entrance of Valdivia River. The fort was undergoing an enlargement when works stopped in 1810. In 1834, when controlled by Chile it worked as deposit for the whole system.
  • San Luis de Alba Fort (not shown in the map)
San Luis de Alba Fort is located in the shores Cruces River north of Valdivia. It was built to secure the land route (Camino Real) to Valdivia where the road passed by the river.
  • Los Torreones (not shown in the map)
Los Torreones (Spanish: The Towers) are two towers built once in what was the outskirts of Valdivia to protect the city against land attacks. The towers are now a local landmark and are used as logo by the local newspaper El Diario Austral de Valdivia.