Aerial view of Lencois Maranhenses National Park, Brazil 20 Jul 2016
About this photo
With more than 155,000 hectares (382,000 acres) of sand dunes, Parque Nacional de Lençóis Maranhenses in Brazil is an ecological paradise. During the rainy season (December to May) hundreds of crystalline lakes are formed. In September to October, wind speeds can reach up to 70km/h (45mph), so visitors to the park are advised to wear sunglasses to protect their eyes.