1. Was built shortly after Saint Peter's death
   Was built on the orders of Emperor Constantine in 324 A.D., was consecrated in 329 A.D., and remains intact today
2. Is a more modern replacement of the original Saint Peter's Basilica and was built in the 16th century

Although some construction spilled over into the early part of the 17th century, the Saint Peter's Basilica that visitors gaze upon today when visiting the Vatican is largely a 16th century replacement of Constantine's original, which had deteriorated badly over the centuries.

1. Are peaceful gardens begun by Pope Nicholas III in 1279 A.D.
   Were victory gardens Pius XII built to sustain the city state during World War II
2. Were a tragic place that witnessed many popes' murders before being uprooted and destroyed in the 1880s by Leo XIII

The original pieces of landscaping that began the lush Vatican Gardens were planted more than 700 years ago -- sprawling, modern gardens still thrive to this day.

1. Is sometimes suspected of being the original work of another painter -- not Michelangelo
   Contains a number of major scenes -- not just the world-famous "Creation of Adam"
2. Was painted with such supreme artistic technique that it has never needed to be repainted or restored

One of Michelangelo's masterpieces, the Sistine Chapel ceiling, contains much more than a scene concerning God's creation of Adam. Many scenes from the Bible are depicted on the lofty fresco -- a fresco that has needed fixing up several times over the centuries.

1. Is an 18-room building built in 1931 that houses a number of famous artistic works collected by several popes
   Is a 15-room building built in 1878 that contains a controversial collection of artifacts from Egyptian antiquity
2. Is a 30-room building built in 1959 that's dedicated to some of the core bureaucratic departments that help run the Vatican

The Vatican Pinacoteca contains masterpieces by a number of renowned artists over the centuries, including Giotto, Pietro Lorenzetti, Raphael, Leonardo di Vinci and Giovanni Bellini, among many others.

1. Is not attached to the main entrance of Saint Peter's Basilica, despite what the name suggests
   Has many of the same features it had when it was completed -- including two main fountains and a massive obelisk, all three erected within the giant elliptical part of the piazza that's ringed with hundreds of columns
2. Broke away from the contemporary Baroque traditions

The piazza retains many of its original attributes, with one notable exception: The entrance used to be more obscured, creating a surprise effect, before the controversial and spacious Villa della Conciliazione opened in 1950.

1. Has been around since the early popes, who built their collection steadily and stealthily
   Is a rather new development. Popes didn't build an actual library until sometime in the 17th century.
2. Fell between antiquity and modernity: The modern Vatican Library has its origins in the 15th century

Evidence of various early libraries and archives dates back to the 4th century, although those collections were often scattered or lost in later years. Many consider the modern era of the Vatican Library to have begun in the 15th century, largely thanks to the efforts of Nicholas V and Sixtus IV, who began rebuilding the Vatican's collection and installing the library in an expanded, physical location. Nowadays, the Vatican Library's holdings are immense.

1. Was sculpted by Michelangelo when he was 24 years old
   Was sculpted by Michelangelo when he was 44 years old
2. Was sculpted by Michelangelo when he was 64 years old

La Pietà was sculpted by Michelangelo when he was just 24 years old, and it was the only piece he ever signed.

1. Aren't really Swiss
   Are responsible for the safety of the Pope, along with Vatican City and Saint Peter's Square
2. Celebrated 500 years of service in 2006

The Pontifical Swiss Guard has had the popes' backs since 1506, when 150 of them first arrived at the Vatican and were blessed by Pope Julius II.

1. Can hold more than 15,000 people
   Was built in the 1800s and was later renovated in the 1960s
2. Is the first Vatican structure to be roofed with a vast array of solar panels

The Paul VI Audience Hall has more than 2,000 solar panels adorning its roof. When they aren't needed to power that building, they can feed into the Vatican's power grid.

1. Doesn't have an official name
   Can be driven by GPS-guided robots
2. Can launch the Pope into the air if he needs to escape

The Popemobile is just an affectionate nickname -- the famous vehicle of the pontiff doesn't have an official designation.