Preservation, stewardship, and resilience in digital knowledge infrastructures of cultural assets refer to the frameworks and practices that support the long-term and sustainable safeguarding of cultural heritage, based on ethical, adaptable and accessible digital systems. This contribution introduces an integrative perspective in the preservation of cultural assets drawn from two recently European-funded research projects, -EXCALIBUR and MusicSphere-, which address distinct yet interconnected domains of cultural heritage through advanced digital technologies and holistic methodological frameworks. Particularly, this contribution presents the main digital toolkits and their key characteristics for enhancing the initiative of the European Collaborative Cloud for Cultural Heritage (ECCCH) [1].

ECCCH, also known as Cultural Heritage Cloud [2,3,4], is a shared platform that will provide heritage professionals with access to data, training material and digital tools to address the various needs concerning the documentation, preservation, and presentation of cultural material. ECCCH infrastructure is based on the principles of Open Access and knowledge-sharing facilitating access to a new generation of highly enriched digital commons using Digital Twins (DT). Meanwhile, both projects leverage high-precision 3D digitization tools, material characterization techniques and AI-assisted simulation to capture physical and mechanical properties, develop dynamic DTs, understand material behavior and support computational reconstruction. Extended reality technologies enable the rigorous visualization and presentation of cultural assets, enhancing interactive accessibility and experiential engagement. In this context, we introduce two research projects, namely MusicSphere [5,6] and EXCALIBUR [7,8] that aim to enhance the ECCCH ecosystem, through different perspectives.

MusicSphere project (A Multimodal Approach for Digitizing, Analysing, and Simulating Traditional Musical Organs Through 3D Technologies, Acoustic Analysis and Interactive Experiences) focuses on the preservation of musical organs, namely church organs and their ancient Greek counterpart, Hydraulis. By combining 3D digitization, acoustic analysis, and simulation, MusicSphere develops detailed DTs of the complex structure and sound behavior of the musical instruments. Moreover, the project extends its research to AI-assisted reconstruction of missing parts of non-functional instruments, as well as spatial acoustics, capturing the mechanical behavior of the environments and validating sound simulation within both ancient and modern soundscapes.

EXCALIBUR project (Advanced toolkits for interdisciplinary and enhanced study, conservation, and restoration in burial excavations and findings) addresses burial sites, tomb structures, artefacts, and human remains within archaeological contexts. It proposes a centralized, interoperable, and human-centered digital infrastructure based on DTs to support enhanced study, conservation, and restoration workflows across multiple contexts – from excavation sites and funerary architecture to artifacts and bioanthropological remains. By integrating heterogeneous datasets, advanced 3D documentation, material characterization, and AI-assisted interpretation within an open and sustainable framework, the project enhances interoperability, transparency, and long-term stewardship of archaeological data.

Both projects emphasize open-source, cost-affordable, and sustainable solutions aligned with ECCCH requirements and framework, ensuring long-term preservation, accessibility, and reuse. They illustrate how multi-functional digital knowledge infrastructures can support cultural heritage resilience by integrating data-driven insights and end-user design into a cohesive ecosystem. This contribution argues that resilience of cultural heritage infrastructures relies not only on technological robustness but also on interoperability, jointly developed scientific knowledge, participatory stewardship, and openness.