San Cristσbal in San Juan in Municipio de San Juan, Puerto Rico — The Caribbean (The West Indies)
In Defense of San Juan
⎯⎯⎯
En defenso de San Juan
San Juan National Historic Site
| | National Park Service, U.S. Department of the Interior | |
At this site you can sample a few of San Juans historic fortifications. Features seen here date from the 1760s through the 1960s, the latter part of San Juans military history.
The concrete blocks scattered on the lawn were left by the U.S. Army, which was here from 1898 through 1960. In fact, the grass-roofed building you are standing on---now housing the park visitor facilities and officeswas built in 1942 as a World War II command post. The other features seen here were all built by Spain, mostly in the late 1700s.
Although fortifications in San Juan cover such a great time span (1521 through 1960), they were all built for the same reason-to defend San Juan and its precious harbor.
Erected by National Park Service, U.S. Department of the Interior.
Topics. This historical marker is listed in these topic lists: Colonial Era • Forts and Castles. A significant historical year for this entry is 1898.
Location. 18° 28.044′ N, 66° 6.672′ W. Marker is in San Juan in Municipio de San Juan, Puerto Rico. It is in San Cristσbal. It can be reached from Bulevar del Valle. Touch for map. Marker is in this post office area: San Juan PR 00901, United States of America. Touch for directions.
Regionally, it is one of the Greater Antilles on the Caribbean Sea, on in the Atlantic Ocean, in North America, in the Western Hemisphere, in the Western World, and in the Anglosphere.
Other nearby markers. At least 8 other markers are within walking distance of this marker: What About Water? / ΏDe Dσnde Viene el Agua? (here, next to this marker); Firepower (here, next to this marker); Three Flags / Tres Banderas (here, next to this marker); The Heart of San Cristobal (here, next to this marker); National Historic Site (here, next to this marker); Historic San Juan / San Juan Historico (about 300 feet away, measured in a direct line); Escuela Josι Juliαn Acosta (about 500 feet away); Casino de Puerto Rico (about 500 feet away). Touch for a list and map of all markers in San Juan.
Credits. This page was last revised on March 30, 2026. It was originally submitted on October 6, 2012, by Don Morfe of Baltimore, Maryland. This page has been viewed 619 times since then and 22 times this year. Photos: 1, 2, 3. submitted on October 6, 2012, by Don Morfe of Baltimore, Maryland. • Bill Pfingsten was the editor who published this page.
Editor’s want-list for this marker. A photo of the complete marker and a transcription of the Spanish text. • Can you help?


