We're in the south of Italy, where many cultures have merged. Alberto Angela takes us to visit the magnificent Valley of the Temples in Agrigento, Sicily.

The temple dedicated to Concordia was built on an ancient seabed from two million years ago, and is one of the most remarkable structures from the Greek world. Alberto Angela explains why it is the only one still standing.

Alberto Angela talks about how Akragas came to be, how its name changed over time, and about what information has been obtained from archeological digs.

Alberto Angela shows us how the Greek Temple of Zeus was built to be seen from great distances.

Although we don't know their function, the Telamons, gigantic statues alternating with the semi-columns of the Temple of Jupiter, were as high as a six-story building. A reconstruction of the temple in the Pietro Griffo Regional Archeological Museum allows us to imagine just how imposing they must have been.

The Ephebe of Agrigento is considered to be one of the masterpieces of Greek sculpture of the fifth century BC in Sicily. It is held in the Regional Archeological Museum of Agrigento, in which we also find a Roman sarcophagus in marble from the second century AD with scenes depicting the life of a child who died at an early age.

We say goodbye to Agrigento's Valley of the Temples and get a close look at the awesome Riace Bronzes in Reggio Calabria. The two life-size Greek bronzes date to the 5th century BC and were discovered off Riace by a scuba diver in 1972.

The first stop is Italy's easternmost point, the Punta Palascìa and its 19th century lighthouse. Alberto Angela then shows us another site in the Apulia region, Castel del Monte, a breathtaking crown-shaped castle built by Frederick II in the early 1200s.

Wonderful aerial photography shows Castel del Monte and its crown-like octagonal shape. Frederick II was particularly fond of the castle because it was an ideal location to hunt small game with his falcons.

Alberto Angela takes us inside Castel del Monte and helps us imagine what it might have looked like when it was "alive." He uses the term piano nobile, which indicates the floor of a mansion where the noblemen or landowners lived, as opposed to the floors where the servants' quarters and kitchens would have been.

As opposed to the classical palaces of the powerful, with their throne rooms and great halls, Castel del Monte has some smaller and more intimate spaces, conducive to more personal encounters. Over the centuries, the castle was exploited in different ways, well into modern times.

We visit the land of the trulli, curious dry stone huts. Alberto Angela gives us some background about these unique dwellings.

Alberto Angelo tells us the fascinating story of how trulli are built. Some of the most characteristic trulli can be found in Alberobello.