Isla Cardona Nature Reserve

Isla Cardona is a small, roughly 6-acre cay located at the entrance to Ponce Harbor on Puerto Rico's south coast, just over a nautical mile from La Guancha. The island is home to the Isla Cardona Lighthouse, built in 1889 during the Spanish colonial period — the only sixth-order lighthouse in Puerto Rico with an attached cylindrical tower — and listed on the U.S. National Register of Historic Places since 1981; it is currently closed to the public due to structural damage. During the 19th century the island served as a quarantine station for contagious diseases, and American troops occupied it during the 1898 Spanish-American War. Surrounded by coral reefs and clear water, it is a popular destination for swimming, snorkeling, and hiking its coastal trails. There are no facilities or dock, so landing requires wading ashore; access is by boat only, with Waterland Adventure as the certified operator offering transport from Paseo Tablado La Guancha.