With updates, modifications and some absences, this text collects the interventions of the conference "Building in the Terra d'Otranto between the Middle Ages and the Modern Age", which took place in Lecce from 11 to 13 July 2019 in the former Ospedale dello Spirito Santo . The acts are a useful contribution to the knowledge of the construction site of Terra d'Otranto, between archaeological, artistic, architectural and urban reading. The essays concern in particular the characteristics of the medieval construction site of Terra d'Otranto and its organization and with reference to peculiar aspects of the architectural language of some buildings, such as for example the basilica of Centoporte in Giurdignano and the basilica of S. Caterina d 'Alexandria in Galatina. The continuity of the building tradition, evident in the 'long duration' of the construction of the masonry technique with 'isometric rows', is articulated in the developments of the architectural language of the works of the sixteenth-seventeenth century modern construction site, in the vaulted systems between the sixteenth and seventeenth centuries and of the corner vaulted structures and basins with ribs and more vaults of Lecce churches studied in their geometry and morphometry. The picture is completed by some essays on the finishes of the facades of the buildings in the Terra d'Otranto, on the intervention techniques of the XVIII century following and preventing future seismic events in Salento and the emblematic case for many of the aforementioned aspects of the castle of Fulcignano in Galatone.