The Vatican, located in Rome, is also referred to as The Holy See. 
Located within this enclave of Rome are the following religious and cultural structures:
St. Peter’s Basilica
the Sistine Chapel
the Vatican Museum
Our sons were fascinated that there are Popes laid to rest in the Vatican. When I went there as a 10-11 year old, I remember being fascinated by the sculpture of the Pieta. There is so much emotion shown in the body language of the Virgin Mary cradling Jesus in her arms.
A big surprise for us as a family (when I went there as a child in 1979) was that the Pope was visiting the Vatican that day!! We had no idea this was going to happen. It was the newly elected Pope John Paul II. A crowd was gathering and I remember the excitement in my mother’s voice when she told us what was about to transpire. My tall 20 year old brother put me on top of his shoulders so that I could see the entrance of the cardinals and Pope. Our 1979 photo is very blurry and our waving hand was in the way!
Since I was the highest of all the spectators, the Pope saw me and I waved to him! It is an unforgettable memory for me.
My sister found this newspaper clipping my mother saved for us re: Pope John Paul II around that time we saw him. He agreed to officiate at the wedding of a janitor’s daughter! Read this poignant article to learn about his kindness and generosity. Click on the picture to enlarge. 
The two most important famous people I’ve seen in person are Pope John Paul II who I waved to and Queen Elizabeth (who waved to a massive crowd that we happened to be in.) Both events happened on trips to Europe and will always be thrilling moments for me.
Swiss Guards at the Vatican.
For Rome highlights and itineraries, click on blog link below: