Poggio Mirteto is a comune is situated in the Tiber Valley area of the region of Latium, Italy. Administratively Poggio Mirteto is in the provin…Poggio Mirteto is a comune is situated in the Tiber Valley area of the region of Latium, Italy. Administratively Poggio Mirteto is in the province of Rieti and geographically this municipality is about 45 kilometres northeast of Rome and about 20 kilometres southwest of Rieti.