Experts examine the Acropolis, revealing the extraordinary building skills and architectural aesthetics that make the Parthenon and other buildings unique.

A look at the Colosseum, which saw the deaths of hundreds of thousands of gladiators, criminals and Christians in the name of popular entertainment.

Insight into the Great Wall of China, a history of the nation written in earth and stone. Battlements and ruins stretch for 50,000 kilometres, a spectacular feat of engineering.