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A dolmen is a type of single-chamber megalithic tomb, usually consisting of two or more vertical megaliths supporting a large flat horizontal capstone or "table". Most date from the early Neolithic (4000–3000 BCE) and were sometimes covered with earth or smaller stones to form a tumulus. Small pad-stones may be wedged between the cap and supporting stones to achieve a level appearance. In many instances, the covering has weathered away, leaving only the stone "skeleton" of the mound intact.

It remains unclear when, why and by whom the earliest dolmens were made. The oldest known are found in Western Europe, dating from c 7,000 years ago. Archaeologists still do not know who erected these dolmens, which makes it difficult to know why they did it.