Research data is essential to facilitate scientific progress, yet, many valuable datasets are hidden on web sites and small repositories or are hard to find due to insufficient metadata. Only a fraction of researchers pro-actively share dataset metadata through public portals, and curation of such metadata collections is costly. Unknown Data will provide means to automatically discover, extract, and publish metadata about research data that is hidden on the Web or in scholarly publications. Thus, the project’s goal is to improve findability and re-usability of research data by (a) improving metadata quality, in particular with respect to authority and use of existing datasets and (b) uncovering datasets that are not yet reflected in public data repositories and registries.