The Pantheon is famous for its dome with a hole in the center. It was originally a Roman temple, but became a Catholic Church (Basilica of St. Mary and the Martyrs) in 609 AD, which is why it was allowed to be preserved so well (while other pagan temples were destroyed)
We were not planning to tour, but when we walked by one day Hadassah excitedly pointed to it and said, "The Pantheon, I wrote a paper on it this year!" and so we went back on our last day in Rome and did a self-guided, audio tour.
