Côa River

[3] Over 100,000 ha (247,105 acres) of land in the Greater Côa Valley have been set aside for rewilding and conservation as Natura 2000 areas.

These are of particular interest due to the high concentration of Paleolithic art, and because these carvings are found outside of caves, on rocks in plain sight: Jean Clottes, a prominent French prehistorian, had confirmed that "is the biggest open air site of paleolithic art in Europe, if not in the world".

[5] The drawings attracted worldwide attention when plans to build a hydroelectric dam across the Côa Valley threatened to submerge them.

Although hydroelectric development was already well underway, outcry from locals, the scientific community and the media led to dam construction being halted in 1995 after a change in the national government following elections.

The Côa Valley Archaeological Park, opened in 1996, was declared a protected UNESCO world heritage site in 1998.