Some 6,700 years ago the residents of the Solnitsata (“The Salt Pit”) prehistoric town in today’s Provadiya in Northeast Bulgaria built what were Europe’s first fortress walls made of stone in order to protect their riches accumulated from the large-scale … Continue reading ‘Salt Pit’ Prehistoric Town in Bulgaria’s Provadiya Built Oldest Stone Fortress Walls in Europe to Protect Its Riches, Archaeologist Says