Scala Regia is a flight of steps in the Vatican City and is part of the formal entrance to the Vatican. It was designed by Gian Lorenzo Bernini.
The official entrance to the Apostolic Palace is the Portone di Bronzo at the north side of St Peter's Square. The door opens to the Scala Regia, which leads up to the Sala Regia, which in turn connects to the Sistine Chapel and the Pauline Chapel. Tourists are allowed to climb the staircase to enter the Sala Regia.
The Scala Regia was built by Antonio da Sangallo the Younger in the early 16th century and was restored by Gian Lorenzo Bernini from 1663 to 1666.
Wikipedia https://en.wikipedia.org/wiki/Scala_Regia_(Vatican)
Address (Unnamed Road), Città del Vaticano 00120, Vatican City
Coordinates 41°54'9.847" N 12°27'16.465" E