The experience of exiting the Medici Chapels of the Basilica of San Lorenzo in Florence takes place in the underground passageway through the new bookshop where the ancient walls found during the works are revealed, and is resolved by means of the invisible glass covering of the sacellum, which allows the staircase to be zenithically lit, offering the visitor exiting the unprecedented and vertiginous view from below of the Chapel of the Princes, the apse of the basilica, and the external wall face of the New Sacristy. Project by Studio di Architettura Zermani Associati