The Ponari nymphaeum of Cassino: first steps towards a new approach

The Ponari Nymphaeum, dating from the first century BC to second century AD, is an important example of Roman residential architecture located in the ancient Roman town of Casinum, at the foothill of Montecassino Abbey. It has a rectangular structure with nine square niches, and was originally decorated with rustic mosaics evoking caves and caverns. Later, the walls were covered with painted plaster imitating marble, consistent with the evolution of Roman taste. The nymphaeum opens onto an atrium with an impluvium, paved with a white mosaic and decorated with paintings simulating a garden (paradeisos) and an isodomic wall structure. The presence of the atrium makes the Ponari nymphaeum unique, distinguishing it from the more common type of nymphaeum as an independent structure. Besides illustrating the different construction and decorative phases of the nymphaeum, the paper describes the survey and documentation techniques used, including laser scanning and photogrammetry, to create 3D digital models and a 2.5D virtual tour. Furthermore, it highlights the critical issues related to the nymphaeum structure and the need for conservation interventions. It emphasises the importance of an in-depth analysis of structural materials and the definition and cataloguing of critical processes and risks, both natural and man-made, that threaten the integrity of the archaeological asset. Finally, it proposes the implementation of multi-criteria monitoring procedures to continuously assess the state of conservation of the Ponari Nymphaeum, thus ensuring its long-term preservation.