Nearby, Imperial Austria's greatest leader, Maria Theresa, looks upon the country's greatest collection of art, the Kunsthistorisches Museum. As you enter, you'll be dazzled by the space and reminded of the former glory of the Habsburg's multi-national empire.

At their peak of power in the 1500s, the Habsburg family ruled Austria, Germany, northern Italy, the Netherlands, even Spain. And this museum offers great art from throughout the realm. The Italian collection is particularly strong.

Around the year 1500, Italy had a Renaissance, or "rebirth," of interest in the art and learning of ancient Greece and Rome. In painting, that meant that Greek gods joined saints and angels as popular subjects.

The collection spans the all-stars of the Italian Renaissance:

Titian — the Venetian — seemed particular intimate with the pre-Christian gods and their antics. Here, in Mars, Venus and Amor, a busy cupid oversees the goddess of love making her case that war is not the answer. Mars — his weapons blissfully discarded, sees her point.

The 22-year-old Raphael captured the spirit of the High Renaissance, combining symmetry, grace, beauty and emotion. His Madonna of the Meadow is a mountain of motherly love. Mary's head is the summit and her flowing robe is the base — enfolding baby Jesus and John the Baptist. The geometric perfection, serene landscape, and Mary's adoring face make this a masterpiece of sheer grace. But the cross the little tykes play with foreshadows their gruesome deaths.

As the baroque age succeeds the Renaissance, it brings more emotion and melodrama. Caravaggio's Rosenkranz Madonna provides a strong contrast to Raphael's super-sweet Madonnas. Caravaggio shocked the art world with brutally honest reality — ordinary Madonnas, hands that seem to speak… saints with dirty feet.

In David with the Head of Goliath, Caravaggio turns a harsh light on a familiar Bible story. David shows off the dripping head of the slain giant. The painting, bled of color, is like a black-and-white crime-scene photo. This David is not a heroic Renaissance Man like Michelangelo's famous statue, but a homeless teen that Caravaggio hired off the street. And the severed head of Goliath… is none other than Caravaggio himself, an in-your-face self-portrait.

Art of the Northern "Renaissance" was different. Funded by the economic boom from Flemish and Dutch trading, it was more secular and Protestant than the Catholic-funded art of the Italian Renaissance. Rather than Madonnas and saints, and Greek gods, you'll see peasants, landscapes, and food.

Paintings are smaller, full of down-to-earth objects, designed to appeal to the thriving merchant class. Northern artists embraced the details, encouraging the viewer to appreciate the beauty in everyday things.

Pieter Brueghel the Elder was the Norman Rockwell of the 16th Century — the undisputed master of the slice-of-life village scene. While a city-slicker himself, Brueghel dressed down to observe country folk at play. Even as he highlighted the rustic simplicity of their lives, he showed their quirks as universal examples of human folly.

In his "Farmers' Dance" there's not a saint in sight, but there is a message. Bagpipes symbolized hedonism. In this scene, the church is ignored while the piper gets all the attention.