MADRID, Jan. 16 (Xinhua) -- A collection of around 300 prehistoric caves in southern Spain have been placed on a list of the 12 monuments which were most under threat in a list drawn up by Europa Nostra and the European Investment Bank Institute as part of the European Year of Cultural Heritage.

The caves in the province of Cadiz are in a pre-selected list, which will eventually be reduced to seven for inclusion of the Seven Most Endangered program.

In press release released on Tuesday, Europa Nostra considers that the caves contain "an exceptional set of Prehistoric Rock-Art Sites developed in an extended period of time of about 20,000 years."

The monument consists of "approximately 300 caves and shelters, within which are paintings and engravings of animals and human figures and symbols of diverse styles, the majority belonging to Iberian Schematic art".

The caves are on the endangered list because of factors such as "biological deterioration, structural damage, misuse and acts of vandalism", with the organization lamenting that "misuse and acts of vandalism have done more damage to these caves than natural processes have in thousands of years."

Some of the caves have been used as rubbish dumping grounds, while some prehistoric paintings have been scratched or had graffiti painted over them. Camp fires in some caves have also caused smoke damage to the ancient art.

This damage "has motivated several organizations and individuals to raise awareness of the serious threats to this important heritage site to the local regional and national authorities".

Unfortunately, Europa Nostra explains, that so far authorities in the region have taken only "minor action... to alleviate the threats".