San Juan National Historic Site ⓘ

On November 19, 1493, Puerto Rico was discovered by Europeans, by Italian explorer and colonizer Christopher Columbus on his second voyage westwards. But it was not until August 1508, when Juan Ponce de León discovered the San Juan Bay, dubbing the area, puerto rico. After raids by French corsairs along the coast and multiple insurrections against the Spanish by the local Taínos in the following decades, it was decreed that San Juan should be fortified.

In 1537, La Fortaleza was constructed. However, its placement is highly critiqued as it provides no protection to the mouth of the port and only protects the new town of San Juan from the south, where the assumption was the attackers were already in the San Juan Bay. Poor placement of La Fortaleza and growing fears of British and Dutch privateers instigated the creation of Castillo San Felipe del Morro (El Morro) in 1539. No further fortifications or general growth occurred in San Juan until 1582 when Captain General Diego Menéndez de Valdés arrived in San Juan to govern the newly upgraded presidio, or military encampment. Menéndez de Valdés added to El Morro, added some of the city’s walls, and created the Boquerón Battery (now Fort San Gerónimo del Boquerón).

These new additions were put to the test, when in 1595 British privateer Sir Francis Drake attacked San Juan. Drake was unsuccessful because of some tactical errors, but also the Spanish were well prepared for a British attack. Not only had Menéndez de Valdés added new fortifications, but a fleet of frigates sitting in San Juan Bay and sunken hulls blocked the entrance of the bay. In 1598 the British attacked again, sending Sir George Clifford to capture San Juan. Clifford intended to not repeat Drake’s mistakes, and attacked the islet in the east, by the Boquerón Battery and San Antonio Bridge. There were no significant fortifications between the Boquerón Battery and El Morro, and Clifford was able to march directly to El Morro. After cutting supplies to El Morro, he successfully acquired a Spanish surrender, but the tropical heat and diseases overwhelmed the British troops and they were forced to retreat and leave the island. In response to these attacks, throughout the following decade the Spanish rebuilt parts of San Juan, reinforced El Morro and the Boquerón Battery, and built a wood fort, San Juan de la Cruz, on El Cañuelo Island. This fort would prove useful as the firepower at El Morro could no longer be avoided without engaging San Juan de la Cruz. And this fort also protected the mouth of the Bayamón River.

At the beginning of the 17th century, the Dutch West India Company began selling slaves, knives, mirrors, cloth, and flour in exchange for tobacco, sugar, dyewoods, and hides. In 1625, these Dutch privateers under the direction of Boudewijn Hendricksz attacked San Juan in hopes of holding a more secure hold in the Caribbean. Hendricksz faced little resistance as the civilians fled and the soldiers were not professionally soldiers, but were a volunteer reserve. However, Hendrickzs did not succeed in capturing San Juan for the Dutch, as while Hendrickzs attacked El Morro, other smaller militias attacked the Dutch. Knowing it was futile, Hendrickzs collected all of the wealth from the civilian homes and burned San Juan to the ground before leaving San Juan for good.

The Spanish Main, the Spanish territories in the Caribbean, South America, and Central America, was weakening as other European powers gained colonies in the area. Fears of recapture were understandable, as various European ships sailed past Puerto Rico en route to their respective colonies. In 1634, construction began on the city walls and a new fort, Castillo San Cristóbal. By 1650, the entire city was encircled with a wall and San Cristóbal was a small land fort, protecting the town from invasions in the east. Around this time, El Espigón, or la Garita del Diablo (the Devil’s Sentry Box), was constructed, providing some protection from the north. However, a fortification just west of El Espigón, La Perla, provided more northerly protection after its construction in the 1660s. (The modern-day barrio La Perla is built where this fort used to be!) Additionally in 1660, the wooden San Juan de la Cruz got an upgrade to masonry.

Although the fortifications were improved and maintained, the soldiers staffing the fortifications were not the well-trained militia Spain wanted in Puerto Rico. In 1765, Field Marshall and Inspector-General Alexander O’Reilly was brought to Puerto Rico to reform the soldiers stationed there. Over the 45 days O’Reilly spent in Puerto Rico, he overhauled the military system and instituted stricter codes. O’Reilly with presidio architect Colonel Thomas O’Daly began planning to improve the fortification of San Juan. For the next 25 years, O’Daly and successors built a defense-in-depth system, focusing on batteries in El Morro, creation of San Cristóbal, sections of the city walls, San Gerónimo, El Cañuelo, and the Boquerón sector. The current designs of El Morro and San Cristóbal are because of O’Daly.

Only seven years after the completion of the fortifications were they tested again. In 1797, General Ralph Abercrombie and Admiral Sir Henry Harvey attempted to replicate Sir George Clifford in 1597, but the new reinforcements prohibited Abercrombie and Harvey to successfully push onto the San Juan Islet. After this attempt, no further pushes upon San Juan were made, except for the random pirate raid.

A hundred years later in 1897, the local citizens succeeded in convincing the government to tear down the southeastern section of the city wall; the Santiago Gate, Ravelin, and Bastion; and parts of San Cristóbal to expand the city outside of the defensive walls. A year later on May 12, 1898, an American Naval Fleet commanded by Admiral William T. Sampson attacked San Juan, striking the fortifications and the city walls. Sampson decided against a landing attempt and left. Two months later, another American invasion occurred; General Nelson A. Miles entered Puerto Rico from the south at Guánica, and intended to rendezvous at San Juan. However San Juan never saw any more military action against the Americans as Span and America negotiated a cease-fire and peace talks resulted in Puerto Rico, Guam, and the Philippines becoming American territories. El Morro and San Cristóbal became parts of the American fort, Fort Brooke, and saw minor World Wars action. In 1949, El Morro and San Cristóbal were transferred from the United States Military to the Department of the Interior, National Park Service.

In 1983, United Nations Educational, Scientific, and Cultural Organization (UNESCO) identified La Fortaleza and San Juan National Historic Site to “outstandingly illustrate the adaptation to the Caribbean context of European developments in military architecture from the 16th to 20th centuries. They represent the continuity of more than four centuries of architectural, engineering, military, and political history.” It is one of eighteen protected UNESCO World Heritage Sites in the Caribbean, and is one of twenty-four sites in the United States.

Puerto Rico has more than 500 years of European history embedded in the walls of Old San Juan.

On November 19, 1493, Puerto Rico was discovered by Europeans, and in 1508 Juan Ponce de León arrived on the island to establish a settlement. San Juan was settled and shortly thereafter construction began on fortifications for the city.

Castillo San Felipe del Morro (El Morro) was under consistent repairs and renovations for 250 years after its initial construction in 1539. From 1898 to 1961, El Morro was a part of the U.S. Army fort, Fort Brooke.

Castillo San Cristóbal was similarly under construction from 1634 through 1790, although the majority of the renovations were conducted from 1765 to 1790. This fort differs from El Morro as El Morro is intended for protection from sea attacks and San Cristóbal is intended for protection from land attacks and sieges.

Fortín San Juan de la Cruz (El Cañuelo) was originally built to provide crossfire in conjunction with El Morro against invading privateers. Eventually the firepower at El Morro was so powerful that it made El Cañuelo obsolete.

Construction on the city walls that would eventually encircle San Juan began the same year as Castillo San Cristóbal, in 1634. These 20 foot thick masonry walls protected the civilians and soldiers inside San Juan from potential invaders. There were four main gates into the city; the San Juan Gate still stands today in the western section of the wall.

In 1983, United Nations Educational, Scientific, and Cultural Organization (UNESCO) identified La Fortaleza (the Puerto Rican Governor’s residence) and San Juan National Historic Site in Puerto Rico as a protected World Heritage Site. It is one of eighteen UNESCO sites in the Caribbean, and is one of twenty-four sites in the United States.

San Juan Timeline – Major Events for the Forts in San Juan Considering researching with us? Read about what we have available for research and the restrictions we have