Cave of Altamira

Altamira is a cave in Spain.

People lived near its opening a very long time ago. Deep inside, they painted animals on the rock. They painted bison, horses and deer. Some of the paintings are red, yellow and black.

The Cave of Altamira lies in Cantabria, in northern Spain, between green hills and a coastal plain. It is almost 290 meters long. Near its entrance is a big room with a ceiling covered with paintings of bison, horses and deer. People call it the Polychrome Room, which means the room of many colors.

The paintings were made by hunter-gatherers, people who found all their food by hunting animals and gathering plants. They used the cave for many thousands of years, between about 36,000 and 13,000 years ago. Altamira was the very first cave where people realized that such old paintings existed.

Altamira lies in central Cantabria, on the border of the municipalities of Santillana del Mar and Reocín, 158.5 m above sea level in the upper part of a karst of Pliocene origin. The Altamira National Museum and Research Centre describes an almost linear cave of almost 290 m: an entrance area with the archaeological deposit and the Polychrome Room, both part of a large vestibule, then a long cave with one large chamber, the Great Hall, ending in a narrow gallery that also holds paintings and engravings.

UNESCO inscribed the Cave of Altamira in 1985 and in 2008 extended the property with seventeen more decorated caves of Asturias, Cantabria and the Basque Country, as the Cave of Altamira and Paleolithic Cave Art of Northern Spain. The museum states that the cave was inhabited between about 36,000 and 13,000 years ago, and UNESCO calls Altamira the first cave in which Palaeolithic cave art was identified.

The cave is inside layers of rock.

Over a long time, big pieces of the ceiling fell down. That made the cave's rooms. Then a rockfall closed the door. The cave stayed dark and still for thousands of years.

Many caves are carved by underground rivers, but the museum explains that Altamira formed mostly a different way. The rock is made of flat layers of a sandy limestone called calcarenite, up to a meter thick, with thin layers of clay between them. Over time, big blocks broke off the ceiling and fell, leaving flat ceilings and a floor covered with fallen blocks.

About 13,000 years ago, one of these rockfalls buried part of the entrance and sealed the cave. Inside, the air stayed very steady, with little change in temperature or moisture. That steady climate helped keep the paintings fresh for thousands of years.

According to the museum, Altamira lies in nearly horizontal strata of calcarenite up to 1 m thick, separated by fine clay layers, within a karst of Pliocene origin. Almost no traces of underground water flow remain: the cave owes its shape to ceiling collapse and gravitational subsidence, which detached large blocks and left flat scars, trapezoidal cross-sections and a floor of fallen blocks.

One of these detachments, about 13,000 years ago, buried part of the entrance where people had lived. The museum's conservation page explains that this collapse gave the interior very high climatic stability, ideal for preserving the art. UNESCO makes the same point for the region's decorated caves in general: they survive so well because the art was made in deep galleries, isolated from the outside climate.

The most famous paintings are on one ceiling.

There are big bison in red and black. There are horses and a huge deer. People also left hand shapes and mysterious signs.

The museum says the cave holds paintings and engravings of bison, horses, deer, hands and mysterious signs, spread along more than 290 meters, with the most in the Polychrome Room. There, horses and bison between 125 and 170 centimeters long share the ceiling with a deer more than 2 meters long.

The artists worked in steps. First they scratched or drew the outline with charcoal. Then they filled the shape with red or yellowish paint. On some bison, they used black to show the darker belly, or charcoal to add hair and the hump. They scratched in the eyes and horns. The museum says the artists also made use of the shape of the rock and of large sizes to make the figures striking.

The museum describes Altamira as a showcase of Palaeolithic technique: drawing, painting and engraving; use of large formats and three-dimensionality; and naturalism alongside abstraction and symbolism. Its figures of bison, horses, deer, goats, hands and signs run through the whole cave, concentrated in the Polychrome Room, where horses and bison measure 125-170 cm and a deer exceeds 2 m.

The process is reconstructed from the paintings themselves: outlines engraved and drawn in charcoal; bodies filled with red or yellowish pigment; black paint or charcoal pencil marking the color change of a bison's belly, the hair or the hump; engraving for eyes, horns and neck hair. UNESCO notes that across the region's decorated caves, researchers have found flint chisels, charcoal pencils, fragments of iron and manganese oxides and even bird-bone tubes used to blow paint, and that no restoration has ever been carried out on the Palaeolithic works, so what survives is entirely original.

The real cave is kept closed to protect the paintings.

Only five people a week may go in. Everyone else visits a copy of the cave in the museum next door. It looks just like the real one!

Visitors can harm a painted cave without touching anything. The museum explains that in the 1900s hundreds of thousands of visitors changed the air inside, making temperatures rise and fall, and paths, walls and electric lights were built. The cave had to close in 1979. It reopened in 1982 for 8,500 people a year, then closed again in 2002.

After a scientific study, only five people a week have been allowed inside since 2015. Everyone else can visit the Neocave at the Altamira Museum, an exact life-size copy of the cave based on study of the methods and materials prehistoric artists used.

The museum's conservation history shows how fragile the cave's microclimate is. In the 20th century, air exchange with the outside and temperature fluctuations caused by hundreds of thousands of visitors, along with walls, roads and electrical installations, destabilized the cave, which closed in 1979; it reopened in 1982 for 8,500 visitors a year. Between 1997 and 2001 surrounding land was bought, livestock facilities removed and roads diverted to keep pollutants from filtering in, and in 2002 the cave closed for preventive conservation.

A research program from 2012 to 2014 studied the impact of human presence on the paintings, and in March 2015 the museum's board adopted a strict access regime of five people a week. Visits were chosen by random draw from 2014-2015; since visits resumed on 15 August 2020, the five weekly visitors come from a waiting list. The Neocave, an exact three-dimensional replica, lets everyone else see the cave as it was when it was inhabited.