Along the banks of the Côa river in Portugal lies an archaeological treasure: 1,000 prehistoric engravings out in open air. When they were discovered in the 90’s, they immediately caused a sensation among historians and archaeologists. They are scattered over a very large area that has not changed much in the past 30,000 years. Along the riverbed, on granite and schist plaques, men engraved signs that special weather and geological conditions have preserved for thousands of years. Today the Côa Valley is part of Unesco’s World Heritage.
