Green sea turtles return to the same stretch of Caribbean beach where they hatched decades earlier, climbing ashore between July and October to excavate nests and deposit clutches of up to 120 eggs. Tortuguero's twenty-two miles of volcanic black sand host the largest green turtle nesting colony in the Western Hemisphere, with peak activity running from late July through September when hundreds of females arrive nightly. The beach corridor, protected since 1975 under Costa Rica's national park system, stretches from Parismina in the south to the Nicaraguan border, a roadless ribbon accessible only by boat or plane. Conservation protocols adopted in the 1980s transformed Tortuguero from a subsistence turtle-hunting village into a model ecotourism destination. Certified local guides, trained by the Caribbean Conservation Corporation and the park service, lead small groups onto designated beach sections after dusk, using red-filtered flashlights to minimize disturbance. Visitors witness the arduous nesting ritual: a female hauls herself above the high-tide line, digs a body pit with her flippers, excavates a teardrop-shaped egg chamber with her rear flippers, then deposits soft-shelled eggs in a process lasting forty-five minutes to an hour. She covers the nest, throws sand in all directions to mask the location, and returns to the sea. The spectacle draws biologists and casual visitors alike. Tortuguero turtle nesting night tours operate under strict quotas, with group sizes capped at ten and beach access limited to authorized segments. Leatherback turtles, the largest living reptiles, nest earlier in the season—March through May—while hawksbill and loggerhead turtles appear sporadically. The park's research station, established in 1955, maintains the longest-running sea turtle monitoring program in the world, tagging thousands of individuals to track migration routes that span the Caribbean basin. Nesting females show remarkable site fidelity, returning to Tortuguero every two to three years across lifespans that can exceed eighty years. The hatchlings that emerge sixty days later face predation from ghost crabs, frigate birds, and caimans before reaching open water, where only one in a thousand survives to adulthood.