Fortress of the Immaculate Conception

Fortress of the Immaculate Conception
El Castillo de la Inmaculada Concepción
El Castillo, Río San Juan Department, Nicaragua
Fortress of the Immaculate Conception
Fortress of the Immaculate Conception Location of the Fortress of the Immaculate Conception within Nicaragua
Coordinates	11°01′09″N 84°23′47″W / 11.0192°N 84.3964°W / 11.0192; -84.3964
Type	Bastion, Fortress
Site information
Controlled by	Nicaragua
Open to the public	Yes
Site history
Built	1673–1675
Built by	Martín de Andújar Cantos
In use	1675–present
Materials	Stone
Battles/wars	Battle for the Río San Juan de Nicaragua (1762) San Juan Expedition (1780)
Garrison information
Past commanders	Lieutenant Colonel Don José de Herrera y Sotomayor (1762)

The Fortress of the Immaculate Conception, (Spanish: El Castillo de la Inmaculada Concepción) is a fortification located on the southern bank of the Río San Juan (San Juan River), in the village of El Castillo in southern Nicaragua. The fortress is situated approximately 6 kilometers from the border with Costa Rica, at the Raudal del Diablo rapids of the San Juan River. It was completed in 1675 as part of a series of fortifications along the San Juan River, to defend against pirate attacks upon the city of Granada (which can be reached by navigating upstream from the Caribbean Sea along the San Juan River into Lake Nicaragua). The settlement of El Castillo and its fortress continued to be strategically important to the Captaincy General of Guatemala until the late 18th century.

An important historic landmark of Nicaragua, the fortress is on a list of sites as an initial stage in achieving World Heritage Site status with the United Nations Educational, Scientific and Cultural Organization (UNESCO).

Gil González Dávila was a Spanish conquistador and the first European to arrive in present-day Nicaragua. After discovering the "freshwater sea" (Lake Nicaragua) on January 21, 1522, he speculated that it discharged into the Caribbean Sea.Francisco Hernández de Córdoba was another Spanish conquistador who founded the city of Granada (the first Spanish colonial city in Central America) on the shore of Lake Nicaragua on December 8, 1524. Under orders from Hernández de Córdoba, an expedition that included Hernando de Soto, Ruy Díaz (the first mayor of Granada) and Sebastián de Belalcázar explored Lake Nicaragua. They succeeded in locating a waterway running eastwards towards the Caribbean Sea, but reported it to be not navigable.Martin Estete, a citizen of Granada, finally discovered the outlet of Lake Nicaragua in 1528 and named it the Río San Juan. Estete was unable to navigate past the rapids however, because the river was low at that time. In 1529, Diego Machuca became the first man to reach the Caribbean Sea from Lake Nicaragua. After circumnavigating the lake in a group of boats, Machuca and his team entered the San Juan River. From here, Machuca led a group of 200 men who advanced by land, taking the same course as the boats. Machuca named the rapids (the rapids which stopped Estete the year before) after himself, and named the port at the mouth of the river San Juan de las Perlas (later known as San Juan del Norte, and now known as San Juan de Nicaragua).