Côa Valley Rock Art: Portugal's Open-Air Ice Age Engravings

The Côa Valley rock art is a vast collection of prehistoric engravings carved on open-air rock surfaces along the Côa river in north-east Portugal. Most of the Palaeolithic images were made between roughly 25,000 and 10,000 years ago and show horses, aurochs, ibex and deer. Discovered during work for a hydroelectric dam, the engravings were saved in 1995 after a famous campaign whose slogan declared that “the engravings can’t swim”.

The valley and its art

The Côa is a tributary of the Douro, flowing north through a steep valley of schist rock near the town of Vila Nova de Foz Côa. Over thousands of years, the smooth vertical faces of the schist offered surfaces on which people could engrave images.

Most famous Palaeolithic art in Europe lies deep inside caves, such as the Altamira cave paintings in Spain or the Lascaux cave paintings in France. The Côa is different: its engravings are in the open air, on riverside rocks that anyone passing through the valley could have seen. This changed how archaeologists thought about Ice Age art, showing that it was not confined to hidden underground spaces.

Surveys have recorded dozens of rock-art sites along the lower Côa and nearby stretches of the Douro, with thousands of individual figures. Well-known groups include Canada do Inferno, Penascosa, Ribeira de Piscos and Quinta da Barca.

What the engravings show

The Palaeolithic figures are mostly animals. Horses, aurochs and ibex are the most common, followed by red deer; fish and a few human figures also appear. They were made by pecking the rock with a hard stone, by fine incision with a sharp tool, or by scraping and abrasion.

Many panels are crowded with overlapping animals. Some figures have two or three heads drawn in different positions, which researchers interpret as a way of suggesting movement, an early form of animation. The images range from a few centimetres to over a metre long.

The valley also holds later engravings from the Neolithic, the Iron Age and historic periods, including warriors and inscriptions. These show that the rocks remained places of meaning for many thousands of years.

Discovery and the dam

In the late 1980s and early 1990s the Portuguese electricity company prepared and began building a large dam on the lower Côa. Archaeological surveys connected to the project identified the first Palaeolithic engravings in 1991, at Canada do Inferno, where the archaeologist Nelson Rebanda recorded them. The discovery became widely known only in late 1994.

A national and international debate followed. The dam would have flooded much of the valley. Students from local schools took up the slogan “As gravuras não sabem nadar” (“the engravings can’t swim”), and archaeologists, journalists and cultural figures joined the campaign.

Some scientists argued, using experimental direct-dating methods, that the engravings were much younger than the Ice Age, which would have weakened the case for saving them. Archaeologists, including João Zilhão, defended a Palaeolithic age based on the style of the animals and comparisons with dated cave art. Later excavations at the site of Fariseu found engraved rock surfaces buried beneath archaeological layers of Palaeolithic age, which strongly supported the Ice Age date.

In November 1995 the new government led by António Guterres suspended work on the dam. In 1996 the Côa Valley Archaeological Park was created to protect and present the engravings, and in 1998 UNESCO added the site to the World Heritage List. In 2010 the listing was extended to include the related site of Siega Verde across the border in Spain.

The park and the museum today

The Côa Valley Archaeological Park manages the sites and runs guided visits, often in four-wheel-drive vehicles along rough tracks, to a small number of rock groups. At Penascosa, night visits use low-angled artificial light to make the fine engravings stand out, as early light would have done for prehistoric viewers.

The Côa Museum, a large concrete building set into the hillside above the meeting of the Côa and the Douro, opened in 2010. It presents the engravings through replicas, photographs and excavated finds, and explains the archaeology of the valley’s hunter-gatherers.

Excavations at nearby occupation sites have recovered stone tools and other remains of the people who made the art. They show that the valley was a regular hunting and living area during the later Ice Age, not just a place visited for ceremonies.

Timeline

• c. 25,000-10,000 years ago: Most Palaeolithic engravings are made.
• 1991: First Palaeolithic engravings recorded at Canada do Inferno.
• Late 1994: The discovery becomes public and the campaign begins.
• November 1995: The Portuguese government suspends the dam.
• 1996: The Côa Valley Archaeological Park is created.
• 1998: The Côa Valley is inscribed as a UNESCO World Heritage Site.
• 2010: The listing is extended to Siega Verde in Spain, and the Côa Museum opens.

Why it matters

The Côa Valley proved that Ice Age people created monumental art in the open landscape, not only in deep caves. It also became one of Europe’s most famous heritage victories, showing how public pressure could halt a major engineering project to protect the past. Today the engravings form one of the largest open-air collections of Palaeolithic art in the world.