This lagoon - Lagoon Tortuguero, is the only natural lake in Puerto Rico, making its protection extra precious. It is also one of the most ecologically diverse spots on the island, listing 717 species of plant and 23 different types of fish. Hiking around this pretty spot yields ocean views, and you can also fish and kayak in the lake – though you’ll have to bring your own equipment. Ask the rangers on duty about the trails, though they’re pretty obvious. Some locals use them for jogging. One of the lake’s stranger problems is its caiman infestation. In the 1990s there was an odd craze to buy striped South American caimans. Locals bought them in their droves, only to discover they don’t make good pets. Hundreds were ditched in the lagoon, with unfortunate results for the ecosystem. Rangers run an extermination program and have succeeded in getting the population under control; in theory, caimans only hunt at night, but you want to watch what you’re doing at all times. To get to Tortuguero from Hwy 22, take Exit 41, take a right on Hwy 2, then left on Rte 687 until you see a big sign for the lagoon on your left.