Which Brazilian national park is known for its white sand dunes and seasonal freshwater lagoons?

Lençóis Maranhenses National Park is the Brazilian park known for sweeping white sand dunes and seasonal freshwater lagoons.

The park occupies a vast stretch of Maranhão’s northeastern coast. Winds push sand inland from rivers and the Atlantic, forming rolling barchan dunes that can rise to about 40 metres. Although the landscape looks like a desert, it receives substantial tropical rainfall, especially between January and May.

Rainwater collects in the low spaces between dunes because an impermeable layer beneath the sand prevents rapid drainage. During the wet season, these basins become clear freshwater lagoons; as the dry season returns, many shrink or disappear. Some lagoons reach about 100 metres in length and 3 metres in depth.

Created in 1981, the park covers roughly 155,000 hectares and includes beaches, mangroves and restingas as well as dunes. It is often confused with Jericoacoara, another northeastern Brazilian coastal destination, but Lençóis Maranhenses is distinguished by its temporary lagoon-filled dune fields.