This review resumes published data on fungal diversity in and within monuments (e.g., religious and secular monuments, museums, and statues), covering a multidisciplinary investigation into the complex interactions between fungi and cultural heritage structures. Fungi represent remarkable adversaries to monuments, potentially compromising their structural integrity and aesthetic value. Based on a bibliographic search of manuscripts published, the knowledge of fungal communities colonizing monuments was comprehensively assessed. This work first describes the diverse fungal species implicated in the degradation of monument materials (e.g., stone, metal, and glass). It elucidates the factors governing fungal colonization and proliferation in and within these structures (e.g., environmental conditions, construction materials, and human interventions). Finally, the efficacy of preservation and restoration techniques to mitigate fungal threats and safeguard our cultural heritage is also discussed. This synthesis highlights the pivotal role of mycological research in heritage conservation, and a platform for future studies to address critical knowledge gaps is provided. Understanding fungal diversity in and within monuments is critical to preserving these invaluable cultural treasures, as it informs targeted conservation strategies and ensures their longevity in the face of fungal challenges.