Fortín de San Gerónimo

Fortín de San Gerónimo de Boquerón
Fort San Gerónimo picture taken from Caribe Hilton Hotel
Location in Puerto Rico
LocationPuerta de Tierra subbarrio, San Juan, Puerto Rico
Coordinates18°27′46″N 66°05′03″W / 18.462841°N 66.084199°W / 18.462841; -66.084199
Area0.4 acres (0.16 ha)
Built1791
ArchitectJuan Francisco Mestre (1791 reconstruction)
Part ofLínea Avanzada (ID97001136)
NRHP reference No.83004199
RNSZH No.2000-(RMSJ)-00-JP-SH
Significant dates
Added to NRHPOctober 11, 1983
Designated RNSZHFebruary 3, 2000

Fortín de San Gerónimo de Boquerón is a small historic fort located at the mouth of the Condado Lagoon in San Juan Islet across from the district of Condado in the barrio of Santurce in San Juan, Puerto Rico.

It was built during the 18th century to replace a smaller battery (called El Boquerón) that stood at the easternmost end of the San Juan islet. The original Boquerón battery was used by the Spanish to defend the city of San Juan from attacks by Sir Francis Drake in 1595 and George Clifford, the third Earl of Cumberland in 1598, who managed to destroy it during his attack. San Gerónimo became part of San Juan's first line of defense, along with the Fortín San Antonio and Escambrón Fort, while the last line of defense was the formidable Castillo San Cristóbal, which guarded the city entrance proper and also defended from land attacks.