Bursting with wildlife, the National Estuarine Research Reserve at Bahía de Jobos is an enormous protected mangrove bay, one of Puerto Rico's largest and least visited patches of coastal wilderness. The Bahía de Jobos covers almost 3000 acres of brackish water, including associated coastal wetlands and 15 offshore mangrove cays known as Los Cayos Caribes. Though the low-lying mangrove marsh won’t impress like El Yunque's overwhelming natural beauty, it’s an excellent place for birdwatching and those seeking wilderness isolation.
Start at the reserve’s Lab & Visitors Center, a great educational nature center where you can learn about the reserve's star billings: brown pelicans, great blue herons, snowy egrets, ospreys, peregrine falcons and American oyster catchers. More than 100 manatees feed here too, but far from shore so you'll rarely see them from land.
You can go on a superb short hike along the Jagueyes Forest Interpretive Trail, which twists around mangroves, wetlands and salt flats for about 30 minutes. The path, mostly on boardwalks, can be reached from the visitors center.
Another short hike heads through mangroves direct from the visitors center, skirting the ruins of old Aguirre.
Signage is scant after vandalism, but both paths are good. The mangroves also make an excellent kayaking route but you'll need to bring your own kayak.