Effigy mounds are earthworks built by Indigenous peoples in North America, primarily between 1000 BCE and 1000 CE. These mounds are shaped like animals, humans, or other symbols and are often found in the Midwest, particularly in states like Wisconsin and Iowa. They served various purposes, including ceremonial functions, burial sites, and territorial markers. The construction of effigy mounds involved carefully piling soil and stones to create distinct shapes. Many of these mounds are associated with the Adena and Hopewell cultures, which are known for their complex societies and rich spiritual beliefs. Today, effigy mounds are protected as important archaeological and cultural sites.