The backstreet cafe in Casablanca was for me a place of mystery, a place with a soul, a place with danger. There was a sense that the safety nets had been cut away, that each citizen walked upon the high wire of this, the real world. I longed not merely to travel through it, but to live in such a city.

As a travel writer I've specialized in gritty, fearful destinations, the kind of places that make a reader's hair stick on end.

The rain of Madre de Dios is similar to that of the Amazon, but there is a petrifying aspect to it, as if it seeks to wound rather than to nurture.

Lured by the wilderness, and by the chance of spotting rare desert elephants, a few intrepid tourists make their way to the Skeleton Coast each year. It's just about as remote as any tourist destination on earth, but one that pays fabulous dividends.

Where does one go in a tremendous city like Calcutta to find insider information? I recalled India's golden rule: do the opposite of what would be normal anywhere else.

During the days I felt myself slipping into a kind of madness. Solitary confinement has an astonishing effect on the mind. The trip was to stay calm and keep myself occupied. I spent hours working out how to break free. But trying to escape would have been instant suicide.

Respect was one thing. Survival was another. It was important that I kept my priorities in the right order.