Dunes are hills of sand formed by the wind, often found in deserts and along coastlines. They can vary in size and shape, creating beautiful landscapes. The movement of sand by the wind causes these formations to shift, making them dynamic and ever-changing. These sandy hills play an important role in the ecosystem, providing habitats for various plants and animals. For example, sea oats help stabilize coastal dunes, preventing erosion and protecting inland areas. Dunes also serve as natural barriers against storm surges and high waves, making them vital for coastal communities.