In the last few years, Conservation of Cultural Heritage has extended its activities into new fields of intervention, and one of these areas concern the monuments inserted in natural sites. In Europe, interventions are being made in order to conserve this Patrimony, by the means of innovating techniques. This article is contextualized in this line of work, and taking as a starting point the results obtained in 1997 in the Thesis Processes of Preventive Conservation using Intervention in the Surroundings in the Dolmen Sites of Munarriko, Landa, Eretza and Gorbeia.