Fuerte El Abanico, Boulevard Norzagaray, San Juan, San Juan Municipio, PR

Significance: It was built 1779-1783 by military engineer Thomas O'Daly, Chief of the Spanish Corps of Engineers in San Juan. It is a bastion-fort in the outer works of Castillo San Cristobal, a fan-shpaed design determined by 3 gun emplacements for cross-fire. Through an embrasure in the parapet of the ravelin to cover the eastern approach of the fort. Of special interest is a system of mining galleries under the terrepleine. This structure appears to have been only slightly modified by 19th-20th century revisions and remains an intact example of the fortifications erected by Spain to protect its holdings in the new world...
Unprocessed Field note material exists for this structure: N103
Survey number: HABS PR-94
National Register of Historic Places NRIS Number: 66000930