Menga, Part Of Twinned Dolmens, Antequera, Spain Stock Photo

Menga Dolmen near the Andalusian city of Antequera, is considered the largest in Europe, and is believed to have been built around 2,500 BC. Historians have speculated the dolmen was used for burial of ruling families, but at the time of its excavation several hundred skeletons were found inside, explained by the perhaps 2,000 years of use.