The "ABC Deposits" project investigates ecosystem responses in cave deposits of the Apuseni Mountains, Romania. Spanning the Middle to Late Pleistocene and the Holocene, the project integrates the concept of bioarchives into cave deposits, shedding light on ecosystem evolution. By analyzing ancient biomolecules from sediments and stalagmites spanning 130,000 years within a palaeoenvironmental context inferred from geological archives, the project aims to address gaps in sedimentary ancient DNA research. The resulting data will advance palaeoecology, provide insights into past ecosystems, and unlock the complexities of ancient communities. The project emphasizes transparency and data accessibility, making all raw and mapped data freely available. Through interdisciplinary approaches, the project will assess the impact of past climate change on community composition, contributing to our understanding of plant-fauna-human interactions and enabling a comprehensive exploration of community dynamics under changing climatic conditions through the integration of palaeogenomics and palaeoecology. The ABC Deposits project aligns with the objectives of the current call by striving to enhance the scientific research reputation in Romania through internationally recognized outcomes in the field of cave deposits and ancient biomolecules. The project aims to foster research teams and attract high-caliber national and international researchers to promote interdisciplinary research in Romania.