Where are sand dunes found besides deserts?

Sand dunes are not exclusive to deserts; they form wherever loose sand is windblown and can accumulate. Beyond arid environments, sand dunes are found in the following locations:1

• Coastal Areas: Large, linear accumulations of sand frequently form immediately landward of the beach. These coastal dunes develop as wind transports sediment from the shore and deposits it against obstructions.2
• Semiarid Regions: Dunes can be found on eroded or abandoned farm fields in semiarid regions, such as parts of the southwestern United States and northwest India.1
• Humid Regions: Many areas that are currently subhumid or humid contain "fixed" dunes—older dunes stabilized by vegetation—which serve as evidence that these regions were once more arid. Examples include the North American high plains, as well as landscapes in Hungary, Mongolia, and Poland.13
• Extraterrestrial Environments: Dunes are also widely distributed on Mars, appearing both within craters and in a sand sea surrounding its north polar ice cap.1