Comprehensive restoration for the Ministry of Education, Culture and Sport, of the Lower Sacristy of this Spanish Property of Cultural Interest. The scope of work consisted of cleaning, salt extraction and recovery of dimensional losses, with significant stonemasonry work and patching with lime mortars, from the cupola lantern to all the walls and flooring. Subsequently the masonry joints were repointed and waterproofing treatments were applied inside, to protect against the high salinity of condensation humidity present. The chapel roof was also waterproofed to prevent leaks from rainfall infiltration. After the job was completed, we edited a book through Ekaba about this Roman Catholic Church, which was designed by the architect Vicente Acero, in 1722.