Le Domus Romane di Palazzo Valentini shared by @cntraveler says: ""The Domus Romane are ancient Roman villas and other structures that were abandoned in antiquity, filled in with debris, and inadvertently used as foundations for Palazzo Valentini, a Renaissance palace turned government office building. They are now underground, obscured by buildings and pavement just beside Piazza Venezia. Booking is required and must be done online."" on Postcard