Para la Naturaleza manages 45 private nature reserves on the island – representing over 25,000 acres – including the very popular Cabezas de San Juan near Fajardo. Part of the Conservation Trust of Puerto Rico, it hopes to fully protect one-third of the island by 2033. Check for its many excellent tours, which include hiking, exploring caves, canyoneering and kayaking on Puerto Rico's bioluminescent waters.

Trips are led by knowledgeable and enthusiastic guides. Rewarding volunteer opportunities also are offered year-round.