The Republic of Siena ends in the 16th century and power goes to Florence, where we go next, to see some of the architectural wonders there.

Franco Calafatti knows a great deal about spices but he also loves to experiment. The star of this segment is cinnamon.

This video focuses on one of the most famous artists of all time, Leonardo da Vinci. In particular, we start looking at one of his greatest masterpieces, the Last Supper.

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.

This fascinating segment is all about salt: Our spice journey takes us to Sicily, where much of Italy's salt is harvested. Franco talks about how salt is life, salt is gold.

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

Franco shows us some infused salts that we would never think of off hand. His descriptions are colorful and make us want to try out these delicacies.

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.