Cabezas de San Juan Nature Reserve
Fajardo, Puerto Rico
The Cabezas de San Juan Nature Reserve (CSJNR) is located in the northeastern tip of Puerto Rico, in the municipality of Fajardo. The word Cabezas—which translates as ‘heads’—refers to three head-like rocky promontories that extend from the mainland into the Atlantic Ocean. Although the Conservation Trust of Puerto Rico acquired its 434.59 acres of unique ecological, aesthetic, and historical value in 1975, the location has been recognized for its strategic importance since pre-Columbian times, as suggested by evidence and artifacts found after preliminary archeological excavations.
To help guide ships traveling through the Vieques and Culebra passage, an imposing neoclassical style lighthouse was built at Las Cabezas in 1880. The structure, known as El Faro de Fajardo, has been in continuous operation since 1882, and is the second oldest of a system of lighthouses built in Puerto Rico
by the Spanish crown. It was included in the National Register of Historic Places in 1981, after being refurbished and rehabilitated for educational and research purposes by the Conservation Trust.
In addition to its great historical value, the CSJNR constitutes one of the most comprehensive examples of Puerto Rico’s natural coastal communities, including both terrestrial and marine ecosystems extending 9 nautical miles off its shoreline. All in all, the Reserve protects 11 ecosystems, more than 800 species and 300 families of which 34 are considered critical species by the Puerto Rico Department of Natural and Environmental Resources (DNER).
One of the most outstanding ecological resources within the Reserve is its bioluminescent lagoon, Laguna Grande, where the natural spectacle of bioluminescence is displayed throughout the year. The mangrove forest surrounding the lagoon also makes it an important coastal ecosystem by facilitating the water transparency that allows for planktonic and benthic communities to develop.
Las Cabezas was officially designated a Nature Reserve by the Puerto Rico Planning Board in 1986, and due to the ecological attributes of the lagoon and its surrounding areas, the DNER designated the Cabezas de San Juan as a Critical Wildlife Area in 2005. By conserving this area, the Conservation Trust of Puerto Rico has also protected its biotic communities, its genetic resources, and its biological diversity.