Europe's "microstates" are scattered far and wide. We'll start at Vatican City, drop by San Marino, hike up to Liechtenstein, speed over to Monaco, and finish high in the Pyrenees at Andorra.

Our first country is ruled by a man from another country, it has less than 1,000 permanent residents, and its birthrate is zero. It's visited by hordes of tourists daily, and it's the capital of a holy empire with more than a billion subjects worldwide. Any guesses?

The Vatican City. This is the smallest independent country on earth. Even though it occupies less than a square mile — this country has its own radio station, newspaper, post office, and a cute little train station. Along with the grandest church on Earth, it has a massive museum. The Vatican is ruled — both politically and religiously — by the pope.

Vatican City is embedded in the city of Rome. It's surrounded by a mighty medieval wall that evokes a less-than-peaceful history.

After the Roman Empire fell in the fifth century, the city of Rome gradually came under control of the pope. In fact, for centuries, the pope was called the "King Pope." Little by little, the "King Pope" built his own empire. At its peak around the 17th century, the "Papal States," as they were called, encompassed much of the Italian peninsula. When the modern nation of Italy was united, it absorbed most of the Papal States, including the city of Rome. But the pope held out.

For sixty years the pope was holed up here, behind the Vatican Walls. Finally, in 1929, the pope and Mussolini signed the Lateran Treaty, establishing the Vatican as its own nation. The garden-like core of the country — where serious administration takes place — is closed to the public.

The Vatican "military" is made up of the Swiss Guard. In 1506, the pope imported mercenaries from Switzerland, who were known for their loyalty and courage. Today, about 100 Swiss soldiers still protect the pope, keep the crush of tourists as orderly as possible… and wear the flamboyant Renaissance-style uniform that tourists just love to photograph.

The Vatican has its own postal service. Many consider it to be more reliable than mailing things from across the street, in Italy… and Vatican stamps are a fun souvenir.

The Vatican is built on the memory and tomb of the first pope, St. Peter. Piazza San Pietro sits on what was the site of a Roman racetrack. Imagine chariots making their hairpin turns around that obelisk.

For added entertainment during the games, Christians were executed here. In about AD 65, the apostle Peter was crucified within sight of this obelisk. His friends buried him in a humble graveyard atop what pagan Romans called the Vatican Hill. For about 250 years Christians worshipped quietly on this spot. Then, when Emperor Constantine legalized Christianity in AD 313, a basilica was built here, and this became the head of the Roman Catholic Church.

Twelve hundred years later, the original St. Peter's was replaced by this, the most glorious church in all Christendom. Upon entering, your first impression is: It's big… over 600 feet long, bathed in glorious sunbeams. It can accommodate thousands of worshippers.

Near the entrance, Michelangelo's Pietà is adored by pilgrims and tourists alike. Here the 25-year-old Michelangelo intends to make the theological message very clear: Jesus — once alive but now dead — gave his life for our salvation. The contrast provided by Mary's rough robe makes his body — even carved in hard marble — seem soft and believable.

The high altar, like so much of the art decorating the Vatican, is a masterpiece by the great Baroque artist Bernini. With sunlight illuminating its alabaster window — as if powering the Holy Spirit, it encrusts the legendary throne of St. Peter with a starburst of Baroque praise.

Directly above the altar which marks the tomb of St. Peter, stands Bernini's bronze canopy, and above that Michelangelo's dome — taller than a football field on end. The inscription declares, in Latin: Tu es Petrus… "You are Peter and upon this rock I will build my church." This is the scriptural basis for the primacy of Rome in the Catholic Church.

A viewing perch gives travelers a close-up look at those huge letters and a heavenly perspective into the church. From the rooftop you can size up the dome you're about to climb. For a close look at Michelangelo's dome-within-a-dome design, lean in as you climb 300 steps to the cupola.

The view from the top is unrivaled: both of the city of Rome… and of the Vatican grounds. You can survey the entire country from this lofty perch. The long rectangular building is the Vatican Museum with the adjacent Sistine Chapel. These buildings and courtyards display some of the greatest art of Western civilization.

Over the centuries the popes have amassed enough art to fill what many consider Europe's richest museum. Long halls are sumptuously decorated with precious tapestries, frescoed ceilings, and ancient statues.

The museum features art from every age. Its exquisite painting gallery includes Raphael's much-loved painting of the Transfiguration. Halls and courtyards are littered with ancient Greek masterpieces — like the Laocoön… so inspirational to the great masters of the Renaissance.

And the pope's apartments tell Christian history — this is the battle in which Emperor Constantine was led by angels and a holy cross both to a key military victory and to his own religious conversion.

And these rooms celebrate pre-Christian philosophy. Here Raphael paints the School of Athens… the who's who of ancient Greek intellectual heroes… many painted with the features of Renaissance greats… Leonardo, Michelangelo… and a self-portrait of Raphael in the black cap.

But of course, we've just scratched the surface. If you're pondering eternity, try covering the Vatican Museum thoroughly.