Vittoriano Museum Complex
This Museum Complex is a vast art gallery with rotating international exhibits in the eastern wing of the monument built for Vittorio Emanuele II, the so-called Vittoriano. For a panoramic view over the city, a glass lift whisks you to the Terrazza delle Quadrighe (Terrace of the Chariots).
If you are curious about the history of Italy, instead, the Museo Centrale del Risorgimento and the Sacrario delle Bandiere are dedicated to XIX and XX centuries and both free to enter. Italy was created as a modern state, actually, only in 1861.