Vatican City is the smallest country in the world.
It is so small that it has only nine hundred inhabitants.
However, it has everything a country needs: a police force, a newspaper, a postal service, large palaces, and even a leader.
But the palaces were made for God, not for people.
And the leader, who is called the pope, is a religious leader, not a rich warrior.
I am Sister Anna. A sister is a nun, a woman who spends her life praying and helping other people.
Here at the Vatican, I also have a job.
I am a Vatican librarian, so I take care of some of the oldest and rarest books in the world.
The Vatican is almost two thousand years old. Jesus' favorite and most faithful follower was Peter, who we call St. Peter.
After Jesus died, St. Peter worked very hard to tell people about Jesus and convince them to become Christians.
But at that time, Christians were persecuted.
So in the year 64, St. Peter was killed and buried in a graveyard called the Vatican.
When more people became Christians, they decided to build a large church on the site where St. Peter was buried.
They called this church St. Peter's Basilica.
St. Peter's Basilica was Christianity's most important church,
and soon after it was built, it became the official residence of the pope, who is the spiritual leader for all Catholics in the world.
By 1506 St. Peter's Basilica was falling apart.
It was also too small for all the church officials and priests who worked there.
So Pope Julius II decided to build a new St. Peter's Basilica that would be the greatest and most impressive church in the world.
Eventually in 1546, Michelangelo, a very famous artist, was hired to oversee the building of the new church.
Look! This is what he built. The most remarkable part of the basilica is the dome, which is 42 meters tall.
But a very strange thing happened while the new church was being built.
The location of St. Peter's gravesite was forgotten.
After many years, people began to wonder whether St. Peter really was buried in the basilica.
Some people said that it was just an old legend and that it was never true.
But in 1939 workers who were repairing the basement made an incredible discovery.
They found a gravesite, and in it was the body of St. Peter.
To protect St. Peter's Basilica and the pope, the Vatican has the smallest army in the world.
Our army, the Swiss Guard, has been the defender of the Vatican for the last five hundred years.
Even though they still wear very old-fashioned uniforms, they are excellent guards.
In order to join this army, you must be from Switzerland, be a Catholic, and be at least 173 centimeters tall.
Today there are about one hundred guards who dedicate their lives to the protection of the pope.
One incredible thing about these guards is that they can stand still without even blinking an eye for hours at a time.
In fact, some people think they look like statues.
Another remarkable part of the Vatican is the Sistine Chapel.
This small church was built between 1475 and 1483.
On the outside, it looks like a very simple, rectangle-shaped church, but the ceiling inside is covered with beautiful paintings by Michelangelo.
In order to paint the ceiling, Michelangelo had to lie on his back and paint with his hands above his body.
It took him a total of six years to complete all the pictures.
These paintings have become world-famous. The pope uses the Sistine Chapel on special occasions.
Since the time of St. Peter, the Catholic Church has always had a pope.
When a pope dies, the other spiritual leaders called cardinals come to the Vatican to choose the new leader.
When they arrive, they are locked inside the Vatican until they elect a new pope.
Every day the cardinals go into the Sistine Chapel to pray and think about which cardinal should be the next pope.
At the end of the day, they vote.
Each cardinal writes a name on a piece of paper.
If they do not agree on a new pope that day, they throw the pieces of paper into the chapel fire and put some water on the fire.
Because of the water, the people watching outside see black smoke rise from the chimney.
The black smoke tells them that the cardinals have not chosen a new pope.
When the cardinals finally agree, they burn the pieces of paper without putting water on the fire. That way the smoke is white.
When the people see the white smoke, they cheer and applaud because they know that a new pope has been elected.
The new pope changes from his black and red cardinal's clothing to the white robes of the pope.
Then he comes out and greets the people.
The new pope leaves his home and moves here to the Vatican.
He becomes the spiritual leader to over one billion Catholics around the world.