Tortuguero, Costa Rica
A national park on Costa Rica's Caribbean coast in Limon Province, reachable only by boat or small plane. Behind the beach, a maze of rainforest canals hosts howler, spider, and white-faced capuchin monkeys, sloths, caimans, crocodiles, and more than 300 bird species, all seen on guided boat trips. Best season: July to October for green turtle nesting, with September into October the overlap when hatchlings begin to emerge; canal wildlife viewing is strong year round. The ocean beach has dangerous currents and is not a swimming beach. Village hotels and canal-side eco-lodges cover lodging; book ahead from July to October.
It combines one of the Western Hemisphere's most important green turtle nesting beaches with a roadless rainforest canal system holding monkeys, sloths, caimans, and more than 300 bird species. With no road access, it stays generally quieter than the parks on the standard tourist loop such as Manuel Antonio. Night turtle walks run under strict park control: licensed guides, small groups, no cameras or white light, on a beach closed to unguided visitors after dark.