Mosaic of a child face is in the entryway to the ticket office of the dome
Not that many visitors know that it is possible to climb up to the top of St Peter’s dome (“cupola”): it is a fantastic experience, and a great opportunity to enjoy a fantastic and dizzying city panorama all around Rome and to admire a top down view of St Peter’s basilica nave.
At the entrance to the basilica, after the security check, there is a sign that directs you to the far right of the portico (past the Holy Door) and to the kiosk for the elevator. Note that the Basilica entrance is on the right side of the colonnade (follow the queue).
You can take the elevator to the roof level (saving 320 steps), but if you want to be on the top of the cupola you must take the stairs for the last portion (551 steps in total). The entrance cost is 7 Euros for elevator and, 5 Euros for stairs.