San Juan is the capital city and most populous municipality in the Commonwealth of Puerto Rico, an unincorporated territory of the United States. As of the 2020 census, it is the 57th-largest city under the jurisdiction of the United States, with a population of 342,259. San Juan was founded by Spanish colonists in 1521, who called it Ciudad de Puerto Rico.
Castillo San Felipe del Morro, commonly known as El Morro(The Promontory), is a large fortress and citadel in the historic district of Old San Juan, Puerto Rico. Commissioned by Charles I of Spain in 1539, it was first built as a fortified tower in honor of Philip II, who oversaw its expansion into a hornwork fort by 1595. Over the next 200 years, especially in the reign of Charles III, El Morro continued to be developed to reach its current form in 1787. Rising 140 ft from the Atlantic shoreline with 18 to 25 ft thick walls, it stands on a steep, rocky headland promontory on San Juan Islet guarding the entry to San Juan Bay, the harbor of Old San Juan. El Morro, alongside La Fortaleza, San Cristóbal, El Cañuelo, and other forts part of the Walls of Old San Juan, protected strategically and militarily important Old San Juan, La Llave de las Indias , from invasion by competing world powers during the Age of Sail.
Castillo San Cristóbal is a fortress in San Juan, Puerto Rico. It was built by the Spanish to protect against land-based attacks on the historic city of Old San Juan. It is part of San Juan National Historic Site.
Old San Juan is a historic district located at the "northwest triangle" of the islet of San Juan in San Juan. Its area roughly correlates to the Ballajá, Catedral, Marina, Mercado, San Cristóbal, and San Francisco sub-barrios (sub-districts) of barrio San Juan Antiguo in the municipality of San Juan, Puerto Rico. Old San Juan is the oldest settlement within Puerto Rico and the historic colonial district of the city of San Juan. This historic district is a National Historic Landmark District named Zona Histórica de San Juan and is listed on the United States National Register of Historic Places as the Old San Juan Historic District. Several historical buildings and structures, particularly La Fortaleza, the city walls, and El Morro and San Cristóbal castles, have been inscribed in the UNESCO World Heritage Site list since 1983. Historically the mixed-use commercial and residential real estate in the main streets of Calle Cristo and Calle Fortaleza from Calle Tanca to the Governor’s Mansion is the most valuable in the area and it has kept its value and increased steadily through several years despite the past economic turmoils.
Fortín de San Gerónimo de Boquerón is a small fort located at the mouth of the Condado Lagoon, across from the historic sector of Miramar in San Juan, Puerto Rico.
Diego de Torres Vargas (1615–1670) was a Puerto Rican Catholic priest, and the first person to write a book about the history of Puerto Rico.
San Juan National Historic Site in the Old San Juan section of San Juan, Puerto Rico, is a National Park Service-managed historic site which preserves and interprets the Spanish colonial-era fortification system of the city of San Juan, and features structures such as the San Felipe del Morro and San Cristóbal fortresses. This fortification system is the oldest European construction under United States jurisdiction and one of the oldest in the New World. This national historic site, together with La Fortaleza, have been designated a UNESCO World Heritage Site since 1983.
Fortín San Juan de la Cruz, most commonly known as El Cañuelo, was built on Isla de Cabras in the Palo Seco barrio of the municipality of Toa Baja, at the western end of the entrance to San Juan Bay, in Puerto Rico. The square coastal fort has massive sandstone walls that date back to the 1630s. Although the U.S. Navy bombarded the fort in 1898, the fort survived. Today the fort is part of the San Juan National Historic Site, which is listed as a UNESCO World Heritage Site and on the National Register of Historic Places. The fort is not open to visitors, but it can be viewed from its exterior.
The recorded military history of Puerto Rico encompasses the period from the 16th century, when Spanish conquistadores battled native Taínos in the rebellion of 1511, to the present employment of Puerto Ricans in the United States Armed Forces in the military campaigns in Afghanistan and Iraq.
San Juan Islet is a 3-square-mile (7.8 km2) islet or small island on San Juan Bay in the Atlantic coast of northern Puerto Rico. Home to Old San Juan, it is the site of the oldest permanent European settlement in Puerto Rico (1521), and the second oldest European settlement in the West Indies after Santo Domingo (1496). Due its strategic location in the Caribbean during the Spanish colonization of the Americas, it is home to a city wall and a number of militaristic buildings such as El Morro Castle. Today, it is also home to many of Puerto Rico's government buildings such as the territory's capitol building.
Isla de Cabras is an islet located at the entrance of the San Juan Bay in Puerto Rico. It is part of the Palo Seco barrio of the municipality of Toa Baja.
Joost van Dyk was a Dutch privateer who was one of the earliest European settlers in the British Virgin Islands in the seventeenth century, and established the first permanent settlements within the Territory. The islands of Jost Van Dyke and its smaller neighbor Little Jost Van Dyke, as well as Little Dix Bay on Virgin Gorda island, are named after him.
Juan de Amézqueta, was a captain in the Puerto Rican Militia who defended Puerto Rico from an invasion by the Dutch in 1625. He fought and wounded Captain Balduino Enrico who was ordered by the Dutch Government to capture Puerto Rico.
José "Pepe" Díaz and Francisco Díaz were two cousins who served as Sergeants in the Toa Alta Militia. Both cousins helped defeat Sir Ralph Abercromby and defend Puerto Rico during an invasion in 1797.
The Third Battle of San Juan began on 28 June 1898 when an American auxiliary cruiser intercepted a Spanish blockade runner. A Spanish squadron attempted to rescue the blockade runner and succeeded in taking off supplies and her crew but failed to save the ship, which the American warship engaged and forced to run aground.
The Bombardment of San Juan, or the First Battle of San Juan, on 12 May 1898 was an engagement between United States Navy warships and the Spanish fortifications of San Juan, Puerto Rico. It was the first major action of the Puerto Rican Campaign during the Spanish–American War.
The Battle of San Juan was a military and naval action on June 15, 1598 when an English force of 20 ships and 1,700 men under Sir George Clifford, Earl of Cumberland, overwhelmed and took the Spanish fortress Castillo San Felipe del Morro and thus took the city of San Juan, Puerto Rico. They were able to hold the castle for 65 days but disease took its toll and the English forces left, but not before sacking and burning San Juan to the ground. This was the only attack that broke through and captured El Morro castle.
Fortín de San Antonio was a fortification built by the Spanish in San Juan, Puerto Rico with the aim of fortifying the San Antonio Bridge. The bridge was of great strategic importance, given that it was the only land accessible entrance to the islet of San Juan. It was located southeast of Fortín de San Gerónimo.
Boudewijn Hendricksz was a Dutch corsair and later Admiral. He is most famous for his role in the Battle of San Juan (1625) during the Eighty Years' War, in which he tried but failed to capture San Juan from Spanish forces. In the same year, prior the assault on San Juan he attempted to recapture Bahia, Brazil after the Spanish overcame Dutch forces in the city.
El Boquerón is a body of water located at the intersection of the Condado Lagoon and the San Antonio Channel in San Juan, Puerto Rico. This body of water separates the Islet of San Juan, where Old San Juan and Puerta de Tierra are located, from El Condado and the Isla Grande peninsula in Santurce. It is separated from the San Antonio Channel by the San Antonio Bridge and from the Condado Lagoon by the Dos Hermanos Bridge. This body of water contains coral reef and habitats important to plant and animal life; it is part of the bigger San Juan Bay National Estuary. These bodies of water are often visited by manatees. The Playita del Condado is located at the eastern end of El Boquerón.
United Provinces 
Juan de Haro y Sanvitores