Mounds

Barrows
Tumuli

Glossary of geology, 1997 (mound (a) A low rounded natural hill, generally of earth; a knoll. (b) A small man-made hill, composed either of debris accumulated during successive occupations of the site (syn: tell; teppe) or of earth heaped up to mark a burial site. (c) An organic structure built by fossil colonial organisms, such as crinoids)
Amer. Heritage dict. of the Engl. lang., c2000 (mound 1. A pile of earth, gravel, sand, rocks, or debris heaped for protection or concealment. 2. A natural elevation, such as a small hill. 3. A raised mass, as of hay; a heap. 4. Archaeology A large artificial pile of earth or stones often marking a burial site)