Evidence suggests that they were not merely decorations of living areas since the caves in which they have been found do not have signs of ongoing habitation.They are also often located in areas of caves that are not easily accessible.
One explanation for this may be that realistically painting the human form was "forbidden by a powerful religious taboo." Pigments used include red and yellow ochre, hematite, manganese oxide and charcoal.
Some theories hold that cave paintings may have been a way of communicating with others, while other theories ascribe a religious or ceremonial purpose to them.
The paintings are remarkably similar around the world, with animals being common subjects that give the most impressive images.
The art is similar in style and method to that of the Indonesian caves as there were also hand stencils and disks made by blowing paint onto the walls.
Cave paintings in El Castillo cave were found to date back to at least 37,300 years old by researchers at Bristol University, making them the oldest known cave art in Europe, 5–10,000 years older than previous examples from France.