St. Peter's Square (Piazza di San Pietro).
Laid out in front of St. Peter's Basilica and over a portion of the Necropolis ("City of the Dead"), this piazza is perhaps one of the most recognizable squares in all of Rome. Along each side are Bernini's breathtaking semi-circular colonnades that give one the feeling that the Basilica is extending its arms outward to envelop the visitor to the church.
On top of the colonnades are 140 marble statues of saints looking down upon the piazza. There are twin fountains midway between Piazza Pius XII and the Basilica's stairs on either side, one by Maderno erected in 1614, and the other was built later to match it.
In the middle of the piazza is a gigantic Egyptian obelisk, originally erected in Heliopolis by King Nuncores and moved to Rome by Emperor Caligula (34-41 A.D.) and set up in the dividing island of his circus in the Vatican Meadows. This circus was later renamed Nero's Circus. As you are facing the Basilica, this former Meadows is to the left of the Basilica, past the left colonnade where Paul VI Hall now stands and where St. Peter was crucified upside down.
As with all obelisks erected in Rome's squares, it is crowed with a bronze cross. This particular obelisk is different than the others in Rome in that within the bronze cross is contained a sliver of the True Cross (Cross of Christ brought back to Rome from Jerusalem by St. Helena). In 1586, Pope Sixtus V moved the obelisk to its present site in the center of the piazza some 100 meters from its original place.
Vatican City is a sovereign country in and of itself, is the smallest nation in the world, and encompasses some 108 acres (about 440,000 square meters) and is completely surrounded by Rome. It includes St. Peter's Basilica (the largest church on earth at over six acres) and the Vatican Museums with over 4-1/2 miles of corridors.