Lençóis Maranhenses National Park is a unique natural reserve located in the northeastern region of Brazil. It is famous for its vast expanse of white sand dunes that stretch over 1,500 square kilometers. The park features seasonal rainwater lagoons that form between the dunes, creating stunning blue and green pools, especially during the rainy season from May to September. Established in 1981, the park is home to diverse ecosystems, including coastal mangroves and freshwater lagoons. It supports various wildlife, including birds and reptiles, making it a popular destination for nature lovers and adventure seekers. Visitors can explore the park through guided tours and hiking trails.