London (7 million inhabitants) was founded on the place of the easiest ford to cross, just before the river widens towards the East to form its estuary. As of the origins, the travellers coming from the continent unloaded in Dover and followed the old roads going from the Kent to London. Ships charged with men and goods sail up the Thames to accost there. The activities of import and export, carried out initially on the quays of the North and South banks of the river, then in the docks built for this purpose at the 19th century, became the heart of the London economy.