Aventine: the famous keyhole

On the Aventine Hill, Piazza dei Cavalieri di Malta was designed by Giovanni Battista Piranesi in 1765. The gate of the Priory of the Knights of Malta hides one of Rome's most surprising views; nearby, the Orange Garden offers a sunset over the Tiber and St Peter's.

Did you know: Put your eye to the keyhole in the gate and you see St Peter's dome perfectly framed by an avenue of hedges — in one glance, three states: the Sovereign Order of Malta, Italy and the Vatican.

✦ The legend: On the Aventine, in the story of Rome's founding, Remus awaited his omens and saw six vultures, while Romulus on the Palatine saw twelve: that decided which hill would become Rome. The keyhole in the gate of the Knights of Malta, by contrast, is an eighteenth-century invention of Giovanni Battista Piranesi, who aligned the garden hedge so that it frames the dome of St Peter's exactly.