Biblioteca Salaborsa (Salaborsa Library), Bologna (must see)

Part of the expansive Municipal Palace ("Palazzo d'Accursio") complex, the Salaborsa Library occupies the former Stock Exchange (Borsa), ingeniously repurposed into a modern multimedia library and cultural hub, designed in Art Nouveau style. Beneath the library's expansive floor, a glass panel in the Covered Square unveils remnants of medieval and Roman settlements, including fragments of the forum and Roman pavement, offering visitors unrestricted access to these historical excavations from the lower basement level.

Before assuming its current role, this sizeable section of the Municipal Palace served a multitude of functions. In 1568, the renowned Bolognese naturalist, Ulisse Aldrovandi, established Bologna's Botanic Garden in the courtyard here, dedicated to the academic exploration of medicinal plants, marking one of Europe's earliest botanic gardens (the present-day botanic garden is located in the university quarter). Subsequently, the courtyard transitioned into a military training ground and later housed bank offices, a puppet theatre, and even a basketball court before being transformed into the Stock Exchange.