3 million visitors visit the Sagrada Familia each year, it is the most visited monument in Spain. Started in 1882 its construction is still not finished. When the Ministry of Territorial Development planned the construction of a railway tunnel just under the main façade of the Sagrada Familia, UNESCO wanted to make sure that the action of the TBM did not present any risks to the iconic monument of Barcelona, built by Gaudi. The static and dynamic monitoring provided by OSMOS confirmed that the monument suffered no damage throughout the work. In case of abnormal trends, the progress of the TBM could be stopped immediately and protective measures could be taken.