In Rome on Pentecost, in the Pantheon, now a minor basilica called S. Maria ad martyres there is a beautiful custom.
Rose petals are dropped through the circular oculus opening at the top of the dome, which is the widest is all of Rome, for all its antiquity. The petals fall to the crowds below, reminiscent of the coming of the Holy Spirit like tongues of flame.
I posted photos taken over two different years here. Some show the event from the inside of the Pantheon, and some show the mechanics from the outside. My room in room is perfectly situated to see the dome of the Pantheon.
Here is how they get it done! Notice the fire truck parked in front of the Pantheon.
The firemen, waiting on top of the dome, for the signal to drop the flower petals…
The moment arrives!
This is one of those lovely customs which we have only in Rome.
Fr. Longenecker found this YouTube piece: