Anta Grande do Zambujeiro is a megalithic monument Valverde – Portugal, one of the biggest existing in the Iberian Peninsula. It was constructed during the range in date from c.4000 B.C. to 3500 B.C.. It consists of a free-standing single-chamber dolmen and was used by the Neolithic communities as a burial place and also possibly for religious purposes. The chamber, of polygonal form, is made of seven large stones that rise 8m above the ground. It was originally covered by a 7m wide stone. The chamber opens into a corridor that is 12m long, 1.5m wide and 2m high, which still retains the original covering stones over much of its length. The entrance was marked by a large, decorated menhir, now lying on the ground.