for several reasons it is unlikely that they were used as habitations, although they may have been used occasionally as hiding-places. silos, or underground storehouses, are well known in the south of europe and morocco. it has been suggested that the grain was stored unthreshed and carefully protected from damp by straw. a curious smoothness of the roof of one of the chambers of the gravesend twin-chamber denehole has been put forward as additional evidence in support of this theory.