The object of study and analysis is the immovable and silent ruin. The Quarantine hospital of Verona, in fact, abandoned to the modeling action of the time, today excites for its state of “isolated ruin” in the landscape context of South Adige Park. The conditio sine qua non of the project of restoration and conservation is the cognitive iter of this tangible ruin, neither dreamlike nor visionary (as those eighteenth-century made by Piranesi). The work began with a topoanalysis of the principal Italian Lazarettos from their birth (1423) to their abandonment, the study of the phenomenon of the plague from a medical point of view, an historical-critique analysis from the urban to the architectural scale.