The five major geographical regions of Italy are the Alps, the Apennines, the Po Valley, the Tyrrhenian Sea, and the Ionian Sea. The Alps are a mountain range that runs along the northern border of Italy. The Apennines are a mountain range that runs through the center of Italy. The Po Valley is a large plain in the north of Italy. The Tyrrhenian Sea is a sea that lies to the west of Italy. The Ionian Sea is a sea that lies to the east of Italy.