Cueva de El Castillo: Red Disks and Hand Stencils in Spain

The Cueva de El Castillo in Cantabria, northern Spain, contains one of the oldest dated examples of cave art in Europe: a red disk painted at least 40,800 years ago. Its walls also carry dozens of hand stencils, rows of red dots and later animal figures, while its entrance holds one of the longest sequences of Stone Age occupation on the continent. Since 2008 it has been part of a UNESCO World Heritage Site.

The cave and Monte Castillo

El Castillo lies in Monte Castillo, a steep cone-shaped limestone hill above the town of Puente Viesgo in the valley of the River Pas. The hill holds several decorated caves, including La Pasiega, Las Monedas and Las Chimeneas, making it one of the richest concentrations of Palaeolithic art anywhere.

The cave consists of a wide entrance area, once used as a living space, and a series of chambers and passages extending deep into the hill. Most of the paintings and engravings are in these darker inner areas.

Discovery and excavation

The Cantabrian researcher Hermenegildo Alcalde del Río found the paintings in 1903, soon after the authenticity of Altamira’s paintings had finally been accepted. He published them in 1911 with the French prehistorian Henri Breuil and Lorenzo Sierra.

Between 1910 and 1914 the German prehistorian Hugo Obermaier, working with Breuil and funded through the Institute of Human Palaeontology in Paris, excavated the entrance deposits. They uncovered a sequence of layers around 18 m deep, with tools of the Acheulean, Mousterian (associated with Neanderthals), Aurignacian, Gravettian, Solutrean, Magdalenian and later periods. From 1980 Victoria Cabrera Valdés directed new excavations that refined this sequence.

Some Aurignacian layers at El Castillo have been dated to around 40,000 years ago or earlier. Their interpretation, and whether they record the very first modern humans in the region, has been debated for decades.

Life at the cave entrance

The thick deposits at the entrance record how different groups used the cave over a very long time. The lower levels contain hand axes and flake tools of the Acheulean and Mousterian traditions, left by earlier human species and later by Neanderthals, who hunted animals such as red deer, horse and bison in the valley.

The upper levels belong to modern humans. Magdalenian layers, roughly 18,000-14,000 years ago, have yielded bone and antler harpoons, perforated antler batons and shoulder blades of red deer engraved with fine outline heads of hinds. Similar engraved shoulder blades are known from Altamira, showing shared artistic conventions across Cantabria.

Few human remains have been found, but fragments of skull and teeth from the upper levels show that people sometimes died or were buried in or near the cave. The site is thus one of the best places in Europe to compare the lives of Neanderthals and early modern humans in the same location.

The art

El Castillo’s art includes hundreds of motifs, painted in red and black or engraved, and made over many thousands of years.

Hand stencils are especially common. They were made by placing a hand flat against the wall and spraying red pigment around it, probably by blowing it from the mouth or through a hollow tube, leaving a negative outline. Hand stencils are among the most widespread forms of early art, found from Europe to Indonesia, Australia and South America.

Different parts of the cave were decorated at different times. The red disks, dots and hand stencils belong to the earliest phases, while many of the animal figures were added much later, in the Solutrean and Magdalenian periods. The dating suggests that people returned to the same walls over many thousands of years, adding new images beside or over older ones.

The best-known areas are:

• The Panel of Hands: a wall with numerous hand stencils, made by blowing red pigment around a hand pressed to the rock, together with red disks.
• The Corridor of Dots: a passage lined with rows of red dots.
• Animal figures: horses, deer, bison and other animals in red, black and engraved lines, mostly from later periods. One bison was painted on a stalagmite so that the natural shape of the rock forms its body.
• Abstract signs: rectangular, club-shaped and other geometric symbols whose meaning is unknown.

The 2012 dating

Most cave art cannot be dated directly, because the pigments contain no organic carbon. In 2012 a team led by Alistair Pike of the University of Bristol, with João Zilhão and Spanish colleagues, sampled thin calcite crusts that had formed over paintings in eleven Spanish caves.

Using uranium-series dating, which measures the radioactive decay of uranium into thorium in the calcite, they obtained minimum ages for the art beneath. At El Castillo a red disk on the Panel of Hands was at least 40,800 years old, and a hand stencil at least 37,300 years old. These were then the oldest dated cave paintings in Europe, older than the figurative art of Chauvet Cave in France.

Because the dates are minimum ages, the red disk could be considerably older than 40,800 years. Other red motifs in the cave also produced early minimum ages, which suggests that this simple, non-figurative art was a lasting early tradition rather than a single episode.

Neanderthals or modern humans?

A minimum age of 40,800 years falls close to the time when Homo sapiens first arrived in northern Spain, and when Neanderthals were still present. The researchers noted that the earliest art could have been made either by newly arrived modern humans or by Neanderthals.

The debate sharpened in 2018, when another team reported uranium-series minimum ages of more than 64,000 years for markings in three Spanish caves, including La Pasiega on the same hill. Such ages would predate modern humans in Europe and point to Neanderthal artists. Other researchers have questioned those samples and methods, and the question remains open.

Visiting and conservation

El Castillo is one of the few major decorated caves in Spain still open to visitors. Tours are guided, groups are small and daily numbers are limited to protect the paintings from changes in temperature, humidity and carbon dioxide. In 2008 the cave was added, with sixteen other caves, to the World Heritage listing originally created for Altamira in 1985.

Visitors are led through the main chambers past the Panel of Hands and a selection of animal figures, with lighting kept low to limit damage. Some of the other decorated caves on Monte Castillo, such as Las Monedas, can also be visited on separate tours under similar restrictions.

Timeline

• Before 100,000 years ago: Early occupation of the cave entrance, with Acheulean and later Mousterian tools.
• At least 40,800 years ago: A red disk is painted on the Panel of Hands.
• At least 37,300 years ago: A nearby hand stencil is made.
• 1903: Hermenegildo Alcalde del Río discovers the paintings.
• 1910-1914: Hugo Obermaier and Henri Breuil excavate the entrance deposits.
• 1980: Victoria Cabrera Valdés begins new excavations.
• 2008, July: El Castillo is added to the UNESCO World Heritage Site of Altamira and Palaeolithic cave art of northern Spain.
• 2012, June: Uranium-series dates for the red disk and hand stencils are published in Science.

Why it matters

El Castillo combines an exceptionally long record of human life with some of Europe’s earliest art. Its red disk and hand stencils are central to the question of when, and by whom, cave painting began in Europe, a question now framed globally by even older dated art in places such as Sulawesi.