BBC presenter Peter White explores London’s Square Mile, from the drama of the stock exchange, through to the changing fortunes of streets where traditional traders are being replaced by wealthy investors. “Most people assume that vast cities like London are intimidating for blind people like me, with their noise and bustle, but in fact give me a busy city any time to the countryside. Noise, to me, means useful signals to navigate by, bustle means people to ask for help, and cities normally promise decent transport and plenty of places to buy the things you need".