The Stadel Museum houses more than 110,000 works of European art from the past 700 years. Since 2012, the museum has been working on expanding its digital content to create this online collection, which allows users to interact with more of the collection than the fraction that can be displayed in gallery spaces. The Stadel digital collection provides a variety of paths to pursue. On the page linked above, in addition to a search with suggested keywords, users can select from thumbnail images to retrieve a work. Visitors can then use the associated metadata to find related works, either from the same artist or style or through clickable keywords leading to conceptually similar materials. For example, starting with Integration Wandlinsen, a 1986 sculpture by Adolf Luther, allows viewers to proceed to discover over 50 works related by concept, time period, artists, or materials. In addition, for those interested in working with museum data, the Stadel Museum digital collection includes all information and tags associated with individual artworks available via an Open Archives Initiative (OAI) interface under a Creative Commons license. To access the OAI interface, users can click on the hamburger icon in the top right corner, then "About the digital collection," then "OAI Interface." The Stadel Museum is located in Frankfurt am Main, Germany.