Francesco Sauro is an explorer of a lost continent - a region of planet earth that stretches for thousands of kilometres.
Francisco Sauro Photo: Stefan Walter - Rolex
Filled with lakes, rivers and waterfalls and inhabited by unique animals - some of which have been cut off from the rest of the world for tens of millions of years.
Dr Sauro specialises in studying the geology of caves and is one of the world's foremost cave explorers.
The crowning achievement of his career so far is the discovery of the world's oldest cave system which can be entered safely.
The Imawarì Yeuta cave system sits within the South American tepuis - flat topped mountains with sheer cliffs on every side rising up out of the Amazon rainforest which were the setting of Sir Arthur Conan-Doyles novel, The Lost World.
He says it was an experience he dreamed about for months and hopes exploring these ancient, preserved worlds will give hints about the origins of life.
Caving was in the blood for Francesco - his father, who was also a cave explorer, first took him underground when he was just three years old.
Today he uses modern technology like satellite images to hunt for entrances to new cave systems and then uses 3D scanning technology to digitally map their interiors.
He's even been involved in training astronauts for the European Space Agency and says working deep underground has many similarities with working in outer space.
Francesco is on a brief break between expeditions and talks to Kathryn Ryan via Skype from his home in Italy.
