Man has always needed to express his concerns and thoughts. When writing did not exist, artistic expression was the perfect resource to convey these ideas. The set of Rock Art of the Mediterranean basin on the Iberian peninsula consists of 757 sites with paintings, and was declared a World Heritage Site in 1998. This is the largest set of rock art sites in Europe. In Catalonia there are the hermitage shelters of the Serra de la Pietat (Ulldecona), Roca dels Moros (Montsià) and the Cave of Vilasos or Els Vilars (Os de Balaguer), among others.
The humans who inhabited the coastal and interior mountains of Aragon, Catalonia, Valencia, Castile-La Mancha, Murcia and Andalusia chose shallow caves and shelters in which to paint and engrave symbols and scenes from their daily life. In every way, the decorated walls also raise many questions about their beliefs, organisation and other aspects which are difficult to understand.
The paintings of the Mediterranean basin were made from the late Palaeolithic period up to the bronze or the iron age. Classified as Levantine art, they express ideas that until that point had been non-existent: man showing his relationship to his environment, the links with nature, beliefs and, at the same time, expressing his power and intervention in the environment in which he lives.
The creators of the cave paintings used different techniques and colours, creating various styles that scholars have classified as naturalist, schematic and macro-schematic. These last two were imposed in the final phase, and tend towards an increasingly accentuated stylisation of the expressions and by an increasing prominence of signs and symbols. The most widely used colour is red, in all its varied tones.