The noise and movement of an elderly Land Rover negotiating a footpath within dense bush was no foil to the impact of the tales of swamp life I was being subjected to. "Of course, you realise that the crocodiles are the least of your worries," the great white pot-bellied hunter paused, wrenched the wheel this way and that, before continuing with great deliberation, "no, the crocodiles will have what is left of you after the hippo have chewed up your dug-out." The 'Hip-po', previously a happy word of the nursery and cartoon, was instantly dismembered by his accent to create a clear onomatopoeic vision of a wobbly dug-out snapping in the jaws of the snarling monster. Turning to look at me in the bright moonlight, my congenial host shared with me a calabash-full of pertinent information. "As for the snakes for which this part of Africa is famous - don't worry, there may be a snake bite kit in the back, but if there is, what use will it be to you? Moments after most snake bites you will be completely paralysed and the polers will be standing around watching you die, for none speak or read a word of English." By the time we reached our fishing camp near the Angolan border at dawn, I believed that I had come to terms with the prospect of travelling alone for at least eight days in such taciturn company; but dying alone in their presence was an untenable thought. To endure that journey down the Okavango to the Kalahari was an early and rigorous introduction to the art of travelling alone, to the condition of being able to survive alone.

Between the concept of travelling alone and the reality of the journey, there exists a gulf that will be bridged by painful as well as pleasing experience. From country to country and culture to culture, the act of travelling alone exposes the myths and expectations of a singular path. No manner of preparation and solitariness will disguise the fact that, by leaving a homeland, one becomes inescapably foreign and obtrusive. How the citizens of each culture will react to this small-time intrusion will make or break the experience of travelling alone. The solitary habit may help the desire to achieve inconspicuousness or it may increase the attention received: within one land one may know just how lonely a journey may be in the close company of others and, yet again, how intrusive a train compartment of strangers may prove. Dependent upon the age and sex of the would-be loner, the choice of destination certainly needs careful thought.

Travelling alone enjoys a different status within the varied regions of the world. Successful solitude may be found in the most unlikely destinations or modes of transport. Without exception, it is very difficult to travel alone outside Europe and North America. Consider how easy it is to take a railway or a bus journey across Europe in delicious isolation from the friendliness of the companions of the carriage. To ignore a possible foreigner is acceptable in those parts - in southern Asia it is unthinkable. If you want isolation from the land and its people when travelling the subcontinent, take the first class air- conditioned wagon or the Air India flight. There you will be forced to endure the foppish company of the politician, the government official or the corporation executive. I take the clamour of second-class reserved and share the ever- proffered tiffin with the broad-beamed smiles of the families in my compartment - and even answer all the questions I am able concerning the greatness of Manchester United, the Spice Girls and Tony Blair. Indeed, I have come to relish, to look forward to these casteless ceremonies of intimate hospitality so alien to my first desire to be alone - despite seeking to be that sentinel of isolation with my open and over-thumbed leaden volume of social history I never fail to pack, never finish and always discard at a faraway hotel for a more appreciative reader.

The obtrusiveness of being foreign has, seemingly, considerable demerits.

Escaping to the Omayid mosque from the demographic froth of the most wonderful Damascene bazaar, I passed through a gate to behold for the first time that temple of temples to monotheism. Bewitched, I entered the cathedral-lofty prayer hall and sat near the tomb of John the Baptist (for reassurance, I suppose) and observed the interplay of women and children, men and boys, at prayer and at play. The all- pervading sense of tranquillity was an unparalleled experience and it was wise to have drunk so deeply, so rapidly, for my peace was to be cast aside by the introduction of a student of agriculture eager to exercise his World-Service English. It was not the interruption that was so galling, but the fact that he was so charming, so genial and good - characteristics that precluded any beastly dismissiveness on my part. As ever, so gentle a meeting converted solitude to a shared and unforgettable experience of being led with gusto to the hidden tombs, chapels and by-ways of ancient Damascus.

Being foreign and a woman alone in certain cultures is an unenviable circumstance. Certain countries are simply not enjoyable to visit for the single woman, whether for the mismatch of the religious, cultural or social mores with our own. Chittagong, like so many conurbations of Muslims the world over, is not a forum for the proselytising of worthy feminine liberal sentiments. The paucity of any kind of foreigners draws undesirable companionship, as mosquitoes to the ear. Boarding a bus, I was approached by an English girl and her train of admirers. After so long in the company of well-wrapped women I was as shocked and confused by the state of her lack of clothing as the gathered young Bangladeshis. The crowd was divided in sentiment - from the full-scale stoning party to lascivious indulgence - and I was delighted when the bus pulled out of the station. I had to ask about her dress, but I should have known that I was wasting my time. Fixing me with a stare that took my eyes permanently away from her partly dressed torso, she stated her view with a certain clarity: "Of course I realise what I should wear. These people simply will have to learn." I forfeited my 45p all-night bus ride and got off before the perimeter of the city.

The personal qualities needed for successful solitary travel are multifarious. Sitting at this desk to map out the requisite facets of character, I wrote: 'foresight, diligence, flexibility and humour'. With a smile I scribbled over these worthy notions and thought of my most memorable expeditions. Many of my journeys were undertaken in a parlous mental condition for, from the experience of travel, I was seeking solutions. It is this balance of being able to allow the outside world to influence one's inward-beseeching world that makes a solitary expedition worthwhile. Take a reserve of worthy notions and a good health insurance policy, for there is nothing more miserable and frightening than to be ill or damaged while on the road alone.

What I appreciate about travelling alone are the extremes of experience so often encountered. The sense of solitude in a tropical land will be acutely felt in the early evening after eating - when the darkness falls like a shutter and the hours before sleep are many. A bright-beamed small torch is essential, for the lighting in inexpensive hotels is never unfailingly diabolical. The slim volumes of my favourite poets are dog-eared from browsing and memorising, and a capacious hip flask of fine whisky is always a soothing companion. By contrast, one may be transported without warning from a cycle of long evenings of quiet thoughtfulness to a night of wayward indulgence. The invasion of my private oceanside guest- house in Cochin by a group of exuberant and friendly New Zealanders resulted in days of parties that became nights with new-found companions, complete with the exhausting surfeit of conversation.

Without companions the pace and direction of travel may vary to one's will. About to depart for the Amazon, I sat within a Quito hotel eating a silent breakfast, seeking not to overhear the siren conversations in English amid the guttural clutter of the local Spanish. From such precocious eavesdropping, I gleaned an introduction to a Galapagos ornithological enthusiast. His vision was an immediate inspiration: "You haff walked a jungle before?" He swung the questions with the directness of a large Swedish wood axe, "Well, you haff seen enough. Go to the Galapagos. If you like wildlife and, most important, the birds, then there is no decision!" So inspired, I ditched an elaborate and painstakingly calculated schedule of buses and aeroplanes and flew west to the Pacific. He was right, there is no decision.

If you had no notion of writing a journal, the action of travel in would-be solitude is the finest inspiration. Not only is there so much more time and space for the quiet dissemination and recording of days past, but the act of mute concentration over a pen and paper will deter all but the most callous interloper of personal privacy.

Whereas the lack of company may be a boon for privacy and quietude, the security of companionship is often sorely missed. That the urban centres of the world are hotbeds of energetic and endemic crime is obvious. The need for vigilance when alone is a source of debilitating fear for many, and so it is best to avoid taking a visible array of baggage that may create so much desire. I feel safest travelling light and take less and less each journey, looking to pack what is worthless to both parties or (as necessary with a camera, travellers' cheques and cash) securely covered by a reliable traveller's insurance policy.

No manner of personal privations, however, will dampen my enthusiasm for the act of travelling alone. The diverse memories I carry from such journeys are legion. From anguish to exhilaration, fulfilment to the most intense and destructive frustration that only alien bureaucracy will create, I may recall the extremes of experience with a shudder or a smile. It is ironic that what makes this practice of attempted solitude so consuming and addictive is the participation of others. Leaving home without a companion is an excellent beginning, for without a partner or friends one may be a susceptible witness to the openness of the human condition that is simple friendship. Of the greatest pleasures of travel, the new-found and often sweetly ephemeral companionship of others is my source of guiding inspiration and steadfast joy.