The first complete conservation treatment of a funerary monument at the protestant Cemetery in Rome marks the beginning of a comprehensive conservation and maintenance programme which follows on the publication of archaeological and historical studies, and a condition survey of the Cemetery's Parte Antica. During treatment it became evident that much of the aesthetic damage and physical deterioration of stone surfaces in that part of the Cemetery was due to its particular environment. There, a lawn sprinkler system showers many of the monuments, thereby aiding erosion and mineral deposition on surfaces, while laurel trees, infested with cochineal, favour algal growth and staining on underlying stone surfaces. Although these environmental conditions have not yet been altered, a complete treatment was carried out on the Lady Temple tomb with commonly used and easily available conservation material, in order to establish a practical methodology and model for planned future work throughout the Cemetery.