The original illuminating apparatus, not changed until after 1898, had an 18-mile (29 km) range and displayed a fixed white light which every three minutes flashed red.

The lighthouse owned by the Puerto Rico Conservation Trust is part of the Las Cabezas de San Juan Nature Reserve.

[3] The 316-acre (128 ha) reserve includes a bioluminescence bay, rare flora and fauna, various trails and boardwalks, and a scientific research center.

Despite its small size, the reserve shelters seven different ecological systems, including beaches, lagoons, dry forest, coral reefs and mangroves.

In 1898, the lighthouse played a major role in the Battle of Fajardo during the Puerto Rican Campaign of the Spanish–American War.