Las Cabezas de San Juan Nature Reserve, a 316-acre property not far from El Yunque, reigns as one of Puerto Rico’s important nature reserves for its eco-habitats and for its preserved lighthouse. Walk along a mangrove-lined boardwalk, stroll sandy beaches, and hike trails through the coastal dry forest. On a moonlit tour of Laguna Grande, witness how dinoflagellates “light up” the water. The climb to the top of El Faro, a restored 19th century lighthouse, first lit by the Spanish in May 1882, offers a sweeping view and insight into how a light functions. You must reserve ahead for admission and for tours, which are offered by the Conservation Trust of Puerto Rico.