In 2020, EPFL introduced ACOUA, a dedicated service designed to manage ‘cold’ datasets, such as supplementary data for articles and doctoral theses, completed research projects, or data retained following the closure of a lab or the departure of a researcher.Initially, the project aimed to address both dissemination and long-term preservation needs. Yet, following the tender process, the implemented service is solely oriented towards preservation. Consequently, ACOUA is a ‘dark’ archive, accessible only to authenticated users. This makes it challenging to communicate to researchers the full value of the service.Overall, ACOUA enables to instate robust and OAIS-compliant workflows from data ingestion and curation to audit and retrieval, backed by detailed documentation and dedicated support for end-users. However, feedback from researchers emphazises the crucial importance of ‘FAIRification‘ for preserved objects. This poster outlines the challenges encountered, strategies applied, and effective solutions implemented to meet the FAIR principles. Highlingts of the state-of-the-art include:FINDABLEA locally developed DataCite v.4.4 metadata generator streamlines the process of adding the metadata files topreserved objects.ACCESSIBLEEach preserved object is assigned a unique DataCite DOI.Pre-signed URLs enable the public access to datasets from ACOUA.A specially developed connector facilitates the automatic transfer of datasets from ACOUA to Zenodo.INTEROPERABLECurrently, we maintain a basic OAI-PMH repository.REUSABLELicenses and readme files are mandatory in ACOUA.DROID characterization and JHOVE validation of file formats are integrated into the process.A checksum check ensures the integrity of retrieved objects. Nevertheless, more needs to be done to reach full FAIRness. The poster also introduces new developments being considered for future work. Examples include, but are not limited to: Use features of the preservation tool to convert files to open formats at ingestions time (SIP), or to prevent obsolescence by evolving file formats on AIP/DIP copies; Explore existing ontologies for specific data collections within ACOUA. Our ultimate goal is to establish ACOUA as a ‘FAIR over time‘ and trustworthy repository, for an enlargedcommunity of re-users.