Tra Esino e San Vicino offers a completely new interpretation of the religious architecture which, between the Romanesque and Gothic periods, established itself in the centre of the Marche region, in an area known as the Valle di S. Clemente. Here, starting in the 11th century, was an extraordinary flourishing of settlements made up of abbeys, hermitages and parish churches, whose oldest structures are often preserved, most of them still legible in their stratigraphy. Through a detailed analysis of the composition of their walls, conducted according to the most modern methodological criteria, and a critical rereading of the written sources, it was possible to reconstruct the different building phases that mark the history of the churches under examination, attesting to the transformations that occurred over time due to changing liturgical needs and frequent destructive events. Thus the articulated architectural-liturgical configurations of some of the most important religious buildings in central Italy were revealed, starting with the crypt of S. Salvatore di Valdicastro, the first tomb of S. Romualdo, where it was possible to recover the liturgical 'functions', as well as some complex and extremely rare structures of which the written documentation bears no trace, such as the women's galleries of S. Elena all'Esino or the internal balconies of S. Urbano and S. Elena all'Esino. In addition, the study proposes a classification of masonry techniques, which made it possible to measure the character of the documented interventions and therefore the role that some magistri and the various construction workers played in the development of the architectural landscape of the area.