The Advanced Defense Line (

Spanish Spanish might refer to: * Items from or related to Spain: **Spaniards are a nation and ethnic group indigenous to Spain **Spanish language, spoken in Spain and many Latin American countries **Spanish cuisine Other places * Spanish, Ontario, Can ...

: Línea Avanzada) is a

historic district A historic district or heritage district is a section of a city which contains older buildings considered valuable for historical or architectural reasons. In some countries or jurisdictions, historic districts receive legal protection from c ...

consisting of four structures that formed part of the eastern defensive system of the Islet of San Juan in

San Juan, Puerto Rico San Juan (, , ; Spanish for "Saint John") 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 jur ...

Components

The

designated by the

United States National Register of Historic Places The National Register of Historic Places (NRHP) is the United States federal government's official list of districts, sites, buildings, structures and objects deemed worthy of preservation for their historical significance or "great artistic ...

consists of two buildings (the

Fortín de San Gerónimo 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. It was built during the 18th century to replace a smaller battery (called E ...

and the San Gerónimo Powderhouse), one structure ( El Escambrón Battery) and the remnants of the San Antonio Bridgehead in El Boquerón.

History

The area where the Advanced Defense Line is located today lies outside of the fortified wall system of San Juan, particularly in the eastern portion of the

Puerta de Tierra Puerta de Tierra is a ''subbarrio'' (subdistrict) occupying the eastern portion of the Islet of San Juan and the ''barrio'' of San Juan Antiguo in the municipality of San Juan, Puerto Rico. The name Puerta de Tierra (Spanish for ''land gate'') ...

sub-district of

San Juan Antiguo San Juan Antiguo (not to be confused with the historic district of Old San Juan which is located within this district), is a barrio located in the municipality of San Juan in the Commonwealth of Puerto Rico. San Juan Antiguo has 7 subbarrios. ...

in the Islet of San Juan. The San Gerónimo Powderhouse, built by military engineer Thomas O'Daly, dates to at least 1769. This powder warehouse is located in modern-day

Luis Muñoz Rivera Park The Luis Muñoz Rivera Park (or Parque Luis Muñoz Rivera in Spanish) is a 27.2 acre (110,000 m2) recreational public space located in Puerta de Tierra in San Juan, Puerto Rico. The park was named in honor of Puerto Rican statesman Luis Muñoz ...

, and it has served many purposes throughout its history from a general warehouse to a history museum to a zoo. Although the city walls of San Juan date to 1634, the eastern portion of the Islet of San Juan was militarily unprotected between

1595 Events January–June * January – Mehmed III succeeds Murad III, as sultan of the Ottoman Empire. * January 17 – During the French Wars of Religion, Henry IV of France declares war on Spain. * April 8 (March 29 O.S.) & ...

- 1598 when

Sir Francis Drake Sir Francis Drake ( – 28 January 1596) was an English explorer, sea captain, privateer, slave trader, naval officer, and politician. Drake is best known for his circumnavigation of the world in a single expedition, from 1577 to 1580 ( ...

and George Clifford, the 3rd Earl of Cumberland respectively attacked the islet until at least 1797 when the British attacked during the Battle of San Juan under the command of

Sir Ralph Abercromby Lieutenant General Sir Ralph Abercromby (7 October 173428 March 1801) was a British soldier and politician. He rose to the rank of lieutenant-general in the British Army, was appointed Governor of Trinidad, served as Commander-in-Chief, Ir ...

and Sir Henry Harvey, at the time of the

Coalition A coalition is a group formed when two or more people or groups temporarily work together to achieve a common goal. The term is most frequently used to denote a formation of power in political or economical spaces. Formation According to ''A Gui ...

Anglo-Spanish War. Although the Spanish and Puerto Rican troops were victorious, this event led to the re-fortification of El Boquerón in the eastern end of Puerta de Tierra. The San Gerónimo Fortress was built after the British attack in the spot of a battery site known as the El Boquerón Battery, which provided southern fire assistance to the northern El Escambrón Battery. Another battery was built nearby at the site of the modern-day San Antonio Bridge which in the 19th century provided rail connection between

Old San Juan Old San Juan ( es, Viejo San Juan) is a historic district located at the "northwest triangle" of the Isleta de San Juan, islet of San Juan. Its area roughly correlates to the Ballajá, Old San Juan, Ballajá, Catedral, Old San Juan, Catedral, Ma ...

and Santurce. Today the San Gerónimo Fortress is located adjacent to the grounds of the

Caribe Hilton Hotel The Caribe Hilton is located in San Juan, Puerto Rico, and is owned by Park Hotels & Resorts and managed by Hilton Worldwide. History In early 1946, as part of the Puerto Rican industrialization effort known as Operation Bootstrap, the Puerto ...

Gallery

File:San Jeronimo aerial.jpg, alt=,

in El Boquerón. File:Polvorin San Geronimo SE corner 2 - San Juan Puerto Rico.jpg, alt=, San Gerónimo Powderhouse in the

. File:Bateria Escambron 2 - San Juan Puerto Rico.jpg, alt=, El Escambrón Battery File:Historic American Buildings Survey, Frederik C. Gjessing, Photographer April 19, 1954 SAN ANTONIO BATTERY, EAST ELEVATION. - Fortifications of San Juan, Outer Defenses, Puerta de HABS PR,7-SAJU,12-8.tif, alt=, San Antonio Bridgehead, site of the former San Antonio Battery in 1954.

References

{{DEFAULTSORT:Línea Avanzada Old San Juan, Puerto Rico Forts on the National Register of Historic Places Historic districts on the National Register of Historic Places in Puerto Rico History of San Juan, Puerto Rico National Register of Historic Places in San Juan, Puerto Rico Spanish Colonial architecture in Puerto Rico Tourist attractions in San Juan, Puerto Rico 1799 establishments in the Spanish Empire 1790s establishments in Puerto Rico Government buildings completed in 1799 Government buildings on the National Register of Historic Places in Puerto Rico