A visit to Costa Rica between March and November coincides with turtle nesting and hatching season. Known as the ‘arribada’ (arrival), thousands of sea turtles emerge from the ocean under the light of a full moon, and lay eggs on Costa Rica’s beaches. This amazing natural phenomenon is an absolute must for wildlife lovers. 

Although you occasionally see turtles nesting by day, the vast majority of the action takes place after nightfall. The pregnant females swim to the shore in droves, and haul themselves up the beach beyond the waterline. There, they will dig nests and lay their eggs, up to 100 at a time, burying them in the warm sand. After seven to ten weeks the baby turtles hatch out of their shells, and as they instinctively set out on the painstaking crawl towards the shore, the battle for survival begins. Running the gauntlet of vultures, dogs, and other predators they must also sidestep the scores of expectant female turtles wading up the beach in the opposite direction. It is a perilous start to life and one reason why the females lay such large numbers of eggs, as many hatchlings do not reach the relative safety of the ocean. But those that do make it to the waves may live for decades, around 30 years for leatherbacks and up to 80 years for green sea turtles. In future years, the female chicks will return as adults to the same beach, to lay their eggs where they themselves hatched, continuing this amazing cycle of life. 

Costa Rica is home to five species of sea turtle: the Olive Ridley, Green Sea turtle, Loggerhead, Hawksbill and the mighty Leatherback. All are endangered: green sea turtles have long been hunted for their meat and eggs, and were almost at the point of extinction when a protection programme was launched in 1955 in Tortuguero. 

Whilst turtle hatching takes place along much of Costa Rica’s coast, for reliable sightings we particularly recommend the protected reserves of Tortuguero on the northern Caribbean coast, and Ostional beach, near Nosara on the Pacific Coasts Nicoya Peninsula. 

Tortuguero’s Turtle nesting season runs from March to October. Tortuguero (Spanish for home of the turtle) is a national park area renowned for its vast numbers of green sea turtles and fewer numbers of hawksbills and enormous leatherbacks. Green sea turtles nest in the region from June to October, peaking in numbers during July and August, whilst the mighty leatherbacks, measuring up to eight feet in length, nest from March to July. 

Ostional National Wildlife Refuge, on the Nicoya Peninsula, was established in 1984. This 200 metre stretch of beach and surrounding ocean is named by the World Wildlife Fund as one of the world’s most important nesting sites for Olive Ridley turtles, who, along with green sea turtles and leatherbacks, flock to lay their eggs on the black volcanic sands. Turtle nesting occurs year round in Ostional but by far the best period to catch the arribada is between September and November, when the numbers of Olive Ridleys can reach their thousands. Occasional sightings are also possible during July and August. November 1995 saw the largest ever arribada recorded in Ostional, with up to half a million females estimated to come ashore. 

To protect the turtles and their nests, and avoid disturbing the nesting and hatching process, the beaches at Tortuguero and Ostional are closed after 6pm daily. After this only guided tours are allowed access - your hotel can arrange a guide for you, tell you where to go and the best time to visit. You will set out after dusk; be sure to wear dark clothing and do not use the flash on your camera. For visitors to Ostional, if you are self-driving to the beach do bear in mind that the route involves a river crossing, which may invalidate the insurance on your rental car. 

Other locations worth mentioning include Playa Grande in Las Baulas National Marine Park, near Tamarindo on the Pacific Coast. This is a key nesting site for Leatherback turtles between October and February. Guided night tours can be booked locally.

The remote Nancite Beach in Santa Rosa National Park, Guanacaste, plays host to thousands of nesting Olive Ridleys during September and October. You will need to get permission from the park ranger to visit the site.