What are sand hills callud?

Sand hills, often referred to as sand dunes, are natural formations created by the accumulation of sand through wind action. These hills can vary in size and shape and are commonly found in desert and coastal environments. They play a crucial role in ecosystems by providing habitats for various flora and fauna and helping to protect shorelines from erosion. The movement and formation of sand hills are influenced by factors such as wind direction, vegetation, and moisture levels.