La Sagrada Familia – although still under construction in Barcelona – is a cathedral without any flaws. Almost 100 years after his death, experts are convinced that Gaudi was a mathematical genius and that each embellishing ornament of the Sagrada Familia actually serves an architectural purpose.

The Mona Lisa by the Italian Renaissance artist Leonardo da Vinci is the most famous painting in the world. What is the secret behind the "real" Mona Lisa? It draws legions of visitors to the Louvre in Paris to contemplate her enigmatic expression. In this "detective story," historians tell us how Leonardo developed the painting and uncover the long-hidden identity of the smiling woman.