Today, San Juan serves as one of Puerto Rico's most important seaports, and is the island's manufacturing, financial, cultural, and tourism center. The population of the metropolitan area, including San Juan and the municipalities of Bayamón, Guaynabo, Cataño, Canóvanas, Caguas, Toa Alta, Toa Baja, Carolina and Trujillo Alto, is about 2 million inhabitants; thus, about half the population of Puerto Rico now lives and works in this area. The city has been the host of numerous important events within the sports community, including the 1979 Pan American Games, 1966 Central American and Caribbean Games, 2006 World Baseball Classic and the Caribbean Series.
In 1508, Juan Ponce de León founded the original settlement Caparra (named after the province Caceres, Spain, the birthplace of then-governor of Spain's Caribbean territories Nicolas de Ovando), which today is known as the Pueblo Viejo sector of Guaynabo, just to the west of the present San Juan metropolitan area. A year later, the settlement was moved to a site then called Puerto Rico, Spanish for "rich port" or "good port," after its similar geographical features to the island of Gran Canaria in the Canary Islands. In 1521, the newer settlement was given its formal name, San Juan Bautista de Puerto Rico, in honor of John the Baptist, following the tradition of christening the town with both its formal name and the name which Christopher Columbus had originally given the island.
The ambiguous use of San Juan Bautista and Puerto Rico for calling both the city and the island led to a reversal in practical use by most inhabitants: by 1746, the name for the city (Puerto Rico) had become that of the entire island, while the name for the Island (San Juan Bautista) had become the name for the city.
San Juan, as a settlement of the Spanish Empire, was used by merchant and military ships traveling from Spain as the first stopover in the Americas. Because of its prominence in the Caribbean, a network of fortifications was built to protect the transports of gold and silver from the New World to Europe. Because of the rich transports, San Juan became a target of the foreign powers of the time. The city was witness to attacks from the English led by Sir Francis Drake in 1595 and by George Clifford, Earl of Cumberland, in 1598. Artillery from San Juan's fort, El Morro, repelled Drake; however, Clifford managed to land troops and lay siege to the city. After a few months of British occupation, Clifford was forced to abandon the siege when his troops began to suffer from exhaustion and sickness. In 1625 the city was sacked by Dutch forces lead by Boudewijn Hendricksz, but El Morro withstood the assault and was not taken. The English attacked again in 1797, during the French Revolutionary Wars, led by Sir Ralph Abercromby (who had just conquered Trinidad). His army laid siege to the city but was forced to withdraw in defeat as the Puerto Rican defenses proved more resilient than those of Trinidad. Various events and circumstances, including liberalized commerce with Spain, the opening of the island to immigrants as a direct result of the Royal Decree of Graces of 1815, and the colonial revolutions, led to an expansion of San Juan and other Puerto Rican settlements in the late 18th and early 19th century.
In May 1898, United States Navy ships, among them the USS Detroit, USS Indiana, USS New York, USS Amphitrite, USS Terror and USS Montgomery, commanded by Rear Admiral William T. Sampson, bombed San Juan during the Spanish-American War, though the city was not occupied. On July 25, General Nelson A. Miles landed at Guánica (in southwestern Puerto Rico) with 3,300 soldiers and took over the island with little resistance. Spain ceded the island to the United States later the same year by signing the Treaty of Paris.
Camp Las Casas, located in the district of Santurce, served as the main training camp for the Puerto Rican soldiers prior to World War I and World War II; the majority of the men trained in this facility were assigned to the 65th Infantry Regiment of the United States Army. This regiment has been active since 1898, and it is still active today. Camp Las Casas was eventually closed down, and in 1950 a public housing project by the name of Residencial Fray Bartolome de Las Casas was constructed on its former location.
Lieutenant Teofilo Marxuach (Retired as a Lieutenant Colonel), a native of Arroyo, Puerto Rico, was responsible for the first bullet shot by the American military during World War I, when he ordered the "Porto Rico Regiment of Infantry" to open fire on the Odenwald, a German armed supply ship, when it was trying to force its way out of San Juan’s bay. This event occurred on April 6, 1917, the day that the United States declared war on Germany.
San Juan is located at, and is suitated along the north-eastern coast of Puerto Rico. It lies south of the Atlantic Ocean; north of Guaynabo and Trujillo Alto; east of and Bayamón; and west of Carolina. The city occupies an area of 76.93 square miles (199.2 km²), of which, 29.11 square miles (75.4 km²) is water. The majority San Juan's water territory is composed of San Juan Bay, and of two natural lagoons, the Condado and the San José.
During the Spanish colonial times most of the urban population resided in what is now known as Old San Juan. This sector is located on the western half of a small island called the Isleta de San Juan, which is connected to the mainland by two bridges and a causeway. The small island, which comprises an area of 47 mi² (122 km²), also hosts the working class neighborhood of Puerta de Tierra and most of Puerto Rico's central government buildings, including the Commonwealth's Capitol. The main central part of the city is characterized by narrow cobblestone streets and picturesque colonial buildings, some of which date back to the 16th and 17th century. Sections of the old city are surrounded by massive walls and several defensive structures and notable forts. These include the 16th century Fort San Felipe del Morro and 17th century Fort San Cristóbal, both part of San Juan National Historic Site, and the 16th century El Palacio de Santa Catalina, also known as La Fortaleza, which serves as the governor's mansion. Other buildings of interest predating the 20th century are the Ayuntamiento or Alcaldía (City Hall), the San José Church (1523) and the adjacent Hotel El Convento, the former house of the Ponce de León family known as Casa Blanca, the Teatro Tapia, the former Spanish barracks (now Museum of Ballajá), La Princesa (former municipal jail, now a history museum), and the municipal cemetery of Saint María Madgalena of Pazzis, located just outside the city walls. The Cathedral of San Juan Bautista (construction began in the 1520s) is also located in Old San Juan, and contains the tomb of the Spanish explorer and settlement founder Juan Ponce de León. Old San Juan, also known as the "old city", is the main cultural tourist attraction in Puerto Rico; its bayside is lined by dock slips for large cruise ships.
San Juan is subdivided into 18 wards (barrios), 16 of which fall within the former (until 1951) municipio of Rio Piedras. Eight barrios are further subdivided in to sub-barrios, including both barrios of the former municipio of San Juan.
East of Old San Juan lies the upscale tourist oriented neighborhood of Condado, which occupies land that used to be owned by entrepreneur Pablo Ubarri Capetillo, a Spanish railroad developer and Count of San José de Santurce under the Spanish colonial period. Beaches such as nearby Ocean Park, popular with swimmers, surfers and kitesurfers, are found all along the district's Atlantic coastline which is also the locus of numerous hotels.
Near Condado are two separate business districts, Santurce and Miramar. Miramar is mainly a residential area rising south of the Condado Lagoon. It comprises the former barrio of Miraflores, as well as drained marshland and landfill over which was built San Juan's first airport, the Isla Grande airport, which was renamed Fernando Luis Ribas Dominicci Airportin honor of Major Fernando Luis Ribas-Dominicci (USAF). Miramar now hosts the Puerto Rico Convention Center as well as some of San Juan Harbor's cruise ship piers. In 2005 Miramar was designated an historical district of Puerto Rico.
Santurce, originally named San Mateo de Cangrejos (Saint Matthew of the Crabs), was a settlement for freed African slaves during the early days of the city. After Pablo Ubarri sought permission to link San Juan with Río Piedra proper via steam tramway in 1878, the time it took to travel between both points were shortened and thereby stimulated the colonization and growth of the district. At the beginning of the twentieth century an electric trolley was installed, the township was split into three parts, and its main settlement, merged with the city, was renamed using the Spanish spelling of Santurtzi (Saint George in Basque), Ubarri's birthplace in Vizcaya, Spain. The "Museo de Arte de Puerto Rico" (Puerto Rico Museum of Art) and other important cultural venues are located in Santurce.
South of Santurce is Hato Rey, part of the former municipality of Río Piedras. Hato Rey was grazing ground for cattle owned by the royal government (hence its name, the King's Herd in Spanish) as early as the 16th century, and is now considered the financial center of the island. A section of this district is often referred to as the "Golden Mile" (actually long) due in part to the many banks and businesses located there.
In the southern part of the city is the socially diversified community of Río Piedras. Founded in the mid 1850s, Río Piedras was a separate town which hosted sugar cane plantations and the estates of some of San Juan's wealthiest inhabitants (as well as their working class staff). The Spanish colonial governors also had their summer home there on land which eventually gave way to the main campus of the University of Puerto Rico. In 1951 the municipalities of San Juan and Río Piedras were merged to redefine San Juan's current city limits. Today Río Piedras comprises the largest area of the municipality of San Juan. and is home to the renowned, traditional “ Plaza del Mercado” (Río Piedras Marketplace), the main campus and the Medical Sciences campus of the University of Puerto Rico and the San Juan Botanical Garden.