Mound structures are earthworks created by various cultures, primarily in North America. These mounds can serve different purposes, including burial sites, ceremonial spaces, or platforms for buildings. They vary in size and shape, with some being conical, while others are more elongated or flat-topped. Many mound structures are associated with ancient civilizations, such as the Mississippian culture and the Adena culture. Notable examples include Cahokia Mounds in Illinois and the Serpent Mound in Ohio. These sites provide valuable insights into the social, religious, and political practices of the societies that built them.