The spiral staircase
Palazzo Farnese — Caprarola, province of Viterbo
In the Rome guidePlan a day here
On screen
Al Neri arrives at the Vatican. On the spiral staircase he waits for Archbishop Gilday and shoots him, and Gilday plunges to the bottom of the stairwell. A deal that began with a generous donation ends in blood.
The place today
A 16th-century pentagonal Renaissance palace designed by Vignola for the Farnese family, on a hill above the village of Caprarola, about an hour from Rome. Its halls are covered in frescoes, among them the Hall of the World Map (Sala del Mappamondo) and the famous spiral staircase, the Scala Regia. It is open as a museum for a fee, with terraced gardens behind.
Also filmed here
Sources: Wikipedia IT