Franceso da Mosto reaches Istanbul, the final stop of his marathon voyage from Venice following the trading routes of the Venetian empire.

Istanbul straddles the Bosphorus as well as two continents. It has been home of both Christian and Islamic civilisations, and Francesco is eager to explore this great city.

First stop is the Palace of Topkapi - centre of power for the Ottoman empire. Most haunting of all is the palace harem, a prison to the sultan's many concubines. Beneath the city is a vast network of underground tunnels dating back more than a thousand years.

Donning hard hat and waders, Francesco enters one of the huge underground cisterns - looking more like a Roman emperor's palace than a water tank. Two giant heads of Medusa lie abandoned in the water.

Istanbul's Grand Bazaar is one of the world's biggest undercover markets and Francesco has a mission in mind. He is going to learn how to sell a Turkish carpet. As he learns the secrets of the trade, he is shown one of the most expensive and beautiful carpets in the city.

A visit to Istanbul would not be complete without the experience of a Turkish bath, however, so Francesco offers himself up for a vigorous soap and scrub. But soon it is time to say goodbye. A final celebration aboard the Black Swan with its long-suffering crew brings Francesco's journey to an end.