Between July and October each year, green sea turtles haul themselves onto Tortuguero's 22 miles of black-sand Caribbean beach to nest — one of only four primary nesting sites for the species in the Western Hemisphere. The ritual has repeated for millennia, but systematic protection began only in 1975 when Costa Rica designated the 77,000-acre coastal corridor as a national park. Archie Carr, the American herpetologist who founded the Caribbean Conservation Corporation here in 1959, calculated that fewer than 300 nesting females returned annually in the late 1950s; by 2025, that figure exceeded 25,000, making Tortuguero the world's most important green turtle rookery. The park's name derives from the Spanish tortuga — turtle — and the Miskito word for the place where turtles come. Four species nest here: green, hawksbill, loggerhead, and the massive leatherback, which can weigh 900 kilograms and travels 10,000 miles between feeding grounds and this narrow ribbon of coast. Nesting occurs nocturnally; females dig flask-shaped chambers above the high-tide line, deposit 80 to 120 eggs, then return to the surf. The entire process takes two hours. Hatchlings emerge 45 to 70 days later, their sex determined by sand temperature during incubation. Beyond the beach, Tortuguero protects 11 distinct habitats: coastal rainforest, palm swamp, herbaceous marsh, and a labyrinth of freshwater canals that parallel the Caribbean for 25 miles. The canal system, built in the 1960s to connect remote coastal villages, now serves as the park's primary access corridor. Boat-based wildlife observation reveals three-toed sloths in cecropia trees, spectacled caimans basking on mudbanks, Jesus Christ lizards running across the water's surface, and more than 400 bird species including the keel-billed toucan and great green macaw. West Indian manatees inhabit the brackish estuaries. Jaguar tracks appear on remote beaches, though sightings remain rare. Visitor access is tightly controlled. All Tortuguero National Park turtle tour entries require advance purchase of a 16.95 USD conservation fee through the SINAC portal; walk-up sales do not exist. Nesting tours operate under strict protocols: groups of ten maximum, red-filtered flashlights only, no camera flash, 10-meter distance from nesting turtles until the egg-laying trance begins. Certified naturalist guides track radio-tagged individuals to minimize disturbance. The park opens at 06:00 daily, and morning canal tours avoid the midday heat that suppresses animal activity. Evening departures target the 20:00 to 02:00 nesting window, when females emerge from the surf.