Burial mounds, also known as tumuli or barrows, are earthworks created to cover graves or burial sites. These structures vary in size and shape, often resembling hills or raised areas, and can be found in many cultures around the world. They serve as memorials for the deceased and can contain artifacts, bones, and other items related to the burial practices of the time. Many burial mounds are associated with ancient civilizations, such as the Mound Builders in North America and the Celtic tribes in Europe. Archaeologists study these mounds to learn about the social, cultural, and religious practices of the people who built them.