At this time, the urban nucleus of Comillas was formed by La Villa square with houses built around it, the late 18th century Town hall and the church of San Cristobal (17th century to 19th). The casonas, many of them Baroque, were remarkable; Tagle, Bracho, Torre, Bustamante, etc., built around the small squares of San Pedro, El Correo and Los Tres Caños. Besides the old 15th century church (at present a graveyard) there were the 17th century hermitages of San Roque and Santa Ana.

The impulse of summer did not make Comillas emerge from its languid rurality. It was in 1875 when the true transformation of the town took place both from an urban-architectural and an economic view, thanks to the Marquises of Comillas (Don Antonio López and Don Claudio López Bru), their family and collaborators. An important group of Catalonian artists helped in the architectural transformation, evolving from eclecticism to Modernism, turning Comillas into a symbol of Spanish architectural development in the latter decades of the 19th century.