A historical building is often a vulnerable system exposed to multiple natural and/or anthropic hazards. It seems to be the case of the 1000-year-old leaning bell tower of Caorle (Venice), whose leaning angle increased during the XX century up to 1.4°. The main interactions between this building and its environment were studied by means of a cost-effective approach based on soil stratigraphy and geomorphological data, geophysical measurements, surveying and historical information on the bell tower and the landscape. The results suggest a probable connection between tilt and overexploitation of water resources in the mid-XX century for agricultural use. In order to exclude other factors, the soil-structure resonant coupling and the effects of the bell ringing were also studied. The results highlight the importance of geoenvironmental sciences in Cultural Heritage preservation. Moreover, the proposed approach can be easily used in every similar context and could be further developed.