The Museum of Contemporary Art of Valdivia is located in an area characterized by high seismic vulnerability. The building and the surrounding area were truly affected by the 1960 earthquake. The edification, built in 1855, is next to the River Valdivia, which undergoes high fluctuation in the salinity. Moreover, the structure suffers of lack of maintenance and the visual inspection denotes different types of damage in different zones. Previous to the rehabilitation, the structure was evaluated with Ground penetrating radar (GPR). The two main objectives of the survey were determining structural arrangement of walls, floor and roof, and to detect possible damage. Visual inspection indicated that some of pathologies were sunken layers, cracks and zones affected by high water content. Many of the damage could be caused by the seismic hazards in the area, and the humid climate. The GPR assessment was carried out with a shielded 800 MHz centre frequency antenna, covering all the different zones of the building.