Lençóis Maranhenses National Park (Parque Nacional dos Lençóis Maranhenses) is a protected area in the state of Maranhão, northeastern Brazil, located just east of Baía de São José. Established on June 2, 1981, the park covers 155,000 hectares (380,000 acres) and includes 70 kilometers (43 miles) of coastline. The interior of the park features large sand dunes. During the rainy season, freshwater lagoons form in the valleys between the dunes because the impermeable rock beneath prevents the water from draining. The park is home to many different species, including four that are endangered, and has become a popular place for people who enjoy nature. In July 2024, the site was recognized as a UNESCO World Heritage Site due to its extraordinary beauty and its status as a one-of-a-kind natural feature in the world.
Physical geography
The park is located on the northeastern coast of Brazil in the state of Maranhão, along the Atlantic Ocean. It has 70 kilometers (43 miles) of beaches. Inland, the park is near the Parnaíba River, the São José Basin, and the Itapecuru, Munim, and Periá rivers. The park covers an area of 155,000 hectares (380,000 acres). Most of the land is made up of large coastal dunes, which formed during the late Quaternary period.
Although the park looks like a desert, it receives about 1,200 millimeters (47 inches) of rain each year. Deserts, by definition, receive less than 250 millimeters (10 inches) of rain yearly. About 70% of the park’s rain falls between January and May.
Sand is brought to the park by the Parnaíba and Preguiças rivers. Wind carries the sand inland up to 50 kilometers (31 miles), forming dunes as tall as 40 meters (130 feet). During the rainy season, which runs from January to June, rainstorms create fresh water lagoons between the dunes. These lagoons can be up to 100 meters (330 feet) long and 3 meters (10 feet) deep. Together, they cover about 41% of the park. A layer of rock below the sand stops the water from draining. The lagoons usually have temperatures between 27.5°C (81.5°F) and 32°C (90°F), a pH between 4.9 and 6.2, and low levels of nutrients. When the dry season returns, the lagoons quickly dry up, losing up to 1 meter (3 feet) of depth each month.
Inside the park, there are two oases called restingas. One is Queimada do Britos, covering 1,100 hectares (2,700 acres), and the other is Baixa Grande, covering 850 hectares (2,100 acres).
The park has an average yearly temperature between 26°C (79°F) and 28.5°C (83.3°F). The temperature changes by about 1.1°C (2°F) each year.
Ecology
The lagoons in the park are often connected to each other and to the rivers in the area. These lagoons are home to many fish and insect species, including the wolf fish, which digs into wet mud and sleeps during the dry season. In addition to the dunes that are the main feature of the park, the ecosystem also includes restinga and mangrove areas.
The park is home to four species that are listed as endangered in Brazil: the scarlet ibis (Eudocimus ruber), the neotropical otter (Lontra longicaudis), the oncilla (Leopardus tigrinus), and the West Indian manatee (Trichechus manatus). The park also includes 133 plant species, 112 bird species, and at least 42 reptile species.
Tourism
Lençóis Maranhenses National Park gets up to 60,000 visitors each year. Popular activities in the park include surfing, canoeing, and riding horses.
In popular culture
The park was shown in the Brazilian movie The House of Sand. A song called "Kadhal Anukkal" from the Indian Tamil movie Enthiran was also filmed there. The movies Avengers: Infinity War (2018) and Avengers: Endgame (2019) used the park's landscape as the planet of Vormir. A concert by the music group RY X was filmed in the park in 2022.