The two Prehistoric Rock Art Sites in the Côa Valley (Portugal) and Siega Verde (Spain) are located on the banks of the rivers Agueda and Côa, tributaries of the river Douro, documenting continuous human occupation from the end of the Paleolithic Age. Hundreds of panels with thousands of animal figures (5,000 in Foz Côa and around 440 in Siega Verde) were carved over several millennia, representing the most remarkable open-air ensemble of Paleolithic art on the Iberian Peninsula.
