The research analyses the geometric characteristics of the different arches that the New Bridge of Ronda (Spain) possesses. This monumental 18th-century engineering work presents a unique morphology among the stone bridges constructed in Spain. From the study of its arches, a comparison is made with the arches of other bridges and aqueducts of similar characteristics. To achieve this objective, through original historical plans of this bridge, digitised and originating from historical archives in Spain, its arches were measured, which was also achieved through current photographs of it. From this, the geometric proportions of said arches are established, allowing their classification into different typologies, as well as the correspondence between what was planned with respect to what was finally constructed. From the results obtained, it is deduced that the geometry of the arches of the New Bridge of Ronda bears a close relationship with the type of arches used since the Roman era in Spain, although characteristics typical of aqueducts are also deduced. Furthermore, the fidelity between what was planned and what was constructed is confirmed, as well as the efficacy of digital tools, such as AutoCAD, in the process followed. All of this allows for a better understanding and documentation of the built heritage, in addition to opening other lines of research in the digitalisation and analysis of this type of construction.