A theme is defined as «an underlying intent or meaning in a work of visual or literary art; also a motif, subject, or idea repeated in a number of artistic works» (Getty Art and Architecture Thesaurus - Getty AAT).

In this section transversal topics – such as music, patriotism, and panoramas - are suggested as research themes and provide another point of access to the single elements, where archival materials, architectural documents, built environment objects and their components, protagonists, and secondary sources are gathered toghether and supported by interpretative essays. Themes section provide a ‘generous interface’ welcoming users by suggesting categories instead of requesting to type a keyword to show its content.