We look at Leonardo's Last Supper from close up — the details, the symbolism — but also from the refectory floor, seeing how Leonardo's genius made the fresco part of the room itself.

Two geniuses left their indelible marks on civilization: Leonardo with the Last Supper and Michelangelo with his David.

This episode will take us to Umbria. We start with one of the most beautiful cities in the region, Assisi, a city that's practically synonymous with the Franciscan monastic order and its founder, Saint Francis.

People often wonder how the Basilica of St. Francis could be as imposing and rich as it is, when the saint to whom it is dedicated had taken an oath of poverty. Alberto Angela explains this and other contradictions.

What did Saint Francis look like? There are clues in a fresco in the lower basilica of the church dedicated to him in Assisi.

We move from the lower basilica to the upper one, which has an entirely different feel to it. Here, we are surrounded by a show of light and color in colorful frescoes and stained-glass windows.

Alberto Angela points out how realistic Giotto's frescoes are compared to earlier ones. He also mentions the important fact that Saint Francis composed one of the first poems in the vernacular

We move from Umbria to Tuscany and visit the evocative ruins of the abbey of San Galgano. Next will be Pisa, a prime example of how Tuscany, in medieval times, was experimenting with very "modern" ideas.

Alberto Angela gives us a look at one of the most famous monuments in the world. We look at the Leaning Tower of Pisa through the lens of those who wanted it built.

Why does the Leaning Tower of Pisa lean? Alberto answers this question and others about one of the most famous monuments in the world.

We go inside the Pisa Cathedral and see how marvelous it is, from the granite columns to the majestic pulpit designed by Giovanni Pisano, which, miraculously, survived the fire of 1595.

We learn a great deal about the third structure at the Piazza dei Miracoli in Pisa: the Baptistery. We learn about wonders we can see and wonders we can't see.

Alberto Angela recounts some interesting facts and legends surrounding the roof of the Bapistery and the Camposanto [cemetery].

Alberto Angela takes us through what is actually a gallery of ancient art inside this cemetery, and focuses on the sarcophagi, each with its story to tell.

We're still at the Camposanto in Pisa. Alberto Angela shows us a wonderful fresco of the Last Judgment, and tells us the story of the artist as well as what is depicted.