The musealization project of the Roman Baths of Chaves arises from a need to interpret, protect, and disseminate a heritage of high value discovered underground in the city center of Chaves. The ruins of the ancient Roman termal complex were discovered at the beginning of this century in Largo do Arrabalde, in the square defined to the north by Rua Cândido dos Reis, to the south by Rua das Longras, to the east by the Court building, and to the west by Largo do Arrabalde. The good state of conservation and extraordinary size of this complex makes it one of the most important in Europe. After its discovery, and over a period of approximately ten years, excavation work was carried out and a building was constructed for the physical protection of the structures. When we won the design competition for the musealization of the space in 2016, we found a large concrete superstructure in plain sight, yet without the capacity and salubriousness for use as a museum.