This remarkable book is primarily about religion, as opposed to the more ambiguous spirituality that is a trend of recent non-fiction. This is a book to make you think seriously about what you believe in, why, and how far you would go for your beliefs, both literally and physically. Mahoney is splendidly human, funny and scholarly, and the book itself is an excellent pilgrimage for anyone to make. She doesn't just detail her six pilgrimages, she explores the theology that gives them meaning, and it is clear from the start that this is a personal quest for divine love, piety and sanctity.

This quest commences with the English shrine of Walsingham, and launches headfirst into the Anglican/Catholic debate which is, apparently, more fierce than ever. Here Mahoney witnesses the rival pilgrimages as well as fanatic protesters, considers the nature of the Church institutions in Britain, and begins to face up to her own almost forgotten Catholic roots as she enters the shrine of Mary and discusses her beliefs with other pilgrims.

Lourdes is an experience of a different kind. Here the humanity and humility of the pilgrims is contrasted with the buildings, which she compares to a concentration camp, but she meticulously details the miracles which have been effected there and explains the theology and doctrine behind them. Her contact with a mother and disabled daughter here is tenderly described, and the reader has a chance to learn from all the people that Mahoney met along the way.

The Camino di Santiago is a grueling walk across Spain, following the ancient legendary bones of St James. That this tale is considered by historians to have no basis in fact has not deterred the pilgrims, and this route has become increasingly popular in recent years. Here the physical hardship of a pilgrimage takes center stage, as Mahoney suffers everything from blisters to crippling tendonitis, but she considers the reasons why people undertake this pilgrimage, with reasons ranging from religious to weight-loss.

Varanasi, the Hindu place of pilgrimage, is a different kind of visit; for a start, it is not the physical hardship and mortification of the flesh that takes center stage here; and Mahoney, like all non-Hindus, was not allowed into the temple. However, she meets an enigmatic and intelligent young boy, Jaga, who lives by his wits in the city. Varanasi is often seen as a city for the dead; many devout Hindus are buried there, and many choose to die there. The extremities of the city - the bustle and the markets - are contrasted with the dead being carried through the streets.

Her trip to the Holy Land is fraught with tension, between Muslims and Jews and between Western and Middle Eastern attitudes towards women, but she wanders the touristy streets of Nazareth as it prepares to celebrate "Nazareth 2000", fights off the unwelcome attentions of the local men, and spends a peaceful and spiritual Christmas in Bethlehem. Rowing alone across the Sea of Galilee she contemplates the various forms of religious belief she has encountered, and spends an unexpected night under the stars considering the nature of the deity.

Finally, she visits St Patrick's Purgatory in Ireland, and undertakes the three-day penitential Catholic pilgrimage, which involves walking barefoot and fasting. Rebellion is on her mind at first, as she struggles even to say the Credo, but inspired by the enthusiasm and love of the other pilgrims she begins to concede. St Patrick's Purgatory has been a place of pilgrimage since the Middle Ages, when a Requiem would be said for each pilgrim as though they had indeed died and entered Purgatory. This and other anecdotes keep Mahoney (and the reader) interested till the end.

On each journey, the reader is invited to join her on her voyage of discovery, through talking to the locals and other pilgrims as well as the reading of books both ancient and modern. This is travel writing at its best: a journey with a purpose, and one that allows reflection on life, death and human endeavor. Mahoney's gift for describing people and situations with warmth and humor is well placed here.