“They are composed of several hundred bones and tusks arranged in a rough circle, between 6 and 10 m (20 and 33 ft) in diameter. A hearth typically lies near the centre of the former dwelling, and stone tools and other debris are scattered within and outside the structure. Large pits filled with stone tools, bone fragements and ash have beenf ound near the houses.
Considerable effort must have been required to assemble these structures. Even in a dry state, large mammoth bones weigh hundreds of pounds.” (HistoryOfInformation)