The Aventine KeyholeFree: All time

Away off the beaten tourist track, on the Aventine Hill, lies the Villa of the Sovereign Military Order of Malta. Prior as being the site for the present Order of Malta, the Villa has seen many occupants including a Benedictine monastery and the Knights of Templars. However, the Villa is arguably best known for a keyhole of the arch-headed central portone, through which the copper-green dome of Saint Peter’s Basilica, the center of Roman Catholicism, can be viewed at the end of a garden framed in clipped cypresses. This keyhole is named The Aventine Keyhole. Perfectly framed, as you peek through the hole, your vision technically cover a view belonging to three countries (Malta, Italy, and Vatican City)!

Address: Piazza dei Cavalieri di Malta 3, Rome, 00153
Direction: Subway Line B to Circo Massimo
Website: en.wikipedia.org/wiki/Villa_del_Priorato_di_Malta

Photo credit: Italy Guides, AngMoKio