The Great Sand Dunes are located in southern Colorado, USA, and are known for having the tallest sand dunes in North America. These dunes rise over 750 feet high and are formed by the wind blowing sand from the nearby San Luis Valley. The area is part of the Great Sand Dunes National Park and Preserve, which was established to protect this unique landscape. Visitors to the Great Sand Dunes can enjoy various activities, such as sandboarding and hiking. The park also features diverse ecosystems, including wetlands and alpine forests, making it a great spot for wildlife observation. Nearby, the Sangre de Cristo Mountains provide a stunning backdrop to the dunes.