Wars, bad designers and strange behaviour - towns don't always get theirnames for the right reasons, writes Shane Hegarty

There is no way of knowing if your town will suddenly become famous, according to Donough O'Brien. It is at the mercy of fate. A dodgy builder made Pisa a tourist attraction. Kyoto came close to being flattened by the atomic bomb, but Hiroshima was chosen instead. The people of Waco, in Texas, will regret the arrival of a cult to their town, while the Bull & Finch pub in Boston is eternally grateful that it doubled as Cheers in the sitcom. Dum Dum, in Calcutta, could have done without giving its name to the infamous bullet.

These are just a few of the entries in Fame By Chance, O'Brien's fascinating A-Z of places unwittingly made famous or infamous. He says the idea came to him while walking past the GPO in Dublin. "I realised that this must be the only world-famous post office." Over a drink he and his wife jotted down places that have become household names. How long did it take him to realise there might be a book in this? "About eight minutes," he laughs.

By the time they left the pub they had come up with 100 places. By the time they had boarded their plane back to London that evening it had reached 200. "After a while I began to realise I was running out of space." The result is 380 entries: the sites of battles and of catastrophes, towns that gave their names to household products, villages where great art was made, sports grounds and famous buildings. The Sea of Tranquillity, site of the first moon landing, ensures it is not all so down to earth.

O'Brien has also found room for fictional places. So between Raffles Hotel and Reading Gaol is an entry for Ramsay Street, made famous by Neighbours. Between Mers-el-Kebir and Midway, second World War battle sites, is Middle Earth, where J. R. R. Tolkien placed battles of a different sort.

"It's a little bit of fun to include these mythical places," says O'Brien. "I know that there's a mixture of quite serious places and jokey or showbusiness ones, but it's the kind of book that people will jump around and read little bits of at a time." It took two years to compile, using books and the Internet.

For those things he knew least about - he admits pop music is a blind spot - he sought help. His brother-in-law took The Archers as his chosen subject on Mastermind, so he was quite handy on Ambridge. His 21-year-old son wrote 50 of the entries, on topics from Reading Gaol to Manzikert, a Turkish village where the Byzantine Empire suffered a vital defeat. Each entry was sent to somebody in the place to confirm the details.

There is much for the Irish reader. Blarney, the Bogside, Béal na mBláth and Clontarf feature, but so do lesser-known places. We learn, for example, that the term "the loo" was coined at a Dublin house party when the host's children replaced the WC sign with the name card of a guest, Lady Louisa. If Oliver Cromwell hadn't vowed to storm Waterford via the village of Crooke, opposite Hook Head, we might not now use the phrase "by hook or by crook".

It's no surprise that there is an Irish bias given that, although English, O'Brien traces his ancestry to Brian Boru and centuries beyond that still.

Last year the former Irish Guard helped his cousin Lord Inchiquin to organise the Brian Boru Festival, which marked 1,000 years since his accession to the throne, and O'Brien is a regular visitor to Banagher, in Co Offaly, where his sister Natalie lives with the singer Roger Whittaker.

He has been to about a third of the places in the book, which is a lot, he admits, given that it includes some fairly obscure spots. His most recent visit was to the Boyne; he says he "screeched the car to a halt to take some pictures" when he realised he was crossing the famous river. Of those he has not visited he would most like to follow the trail of the Great Hedge of India, a 1,500-mile barricade grown by the British in 1854 to enforce the collection of salt taxes. It was the world's second largest man-made structure, behind the Great Wall of China. "It was barbaric," says O'Brien, "one of the worst things the British ever did."

He has spent his publicity tour for the book hearing of all the places he should have included. With interest from Israeli and US publishers among others, he is considering doing editions for individual countries. Having just visited the set of Fair City, he says Carrigstown would make an Irish edition, as would Clonakilty, home of the black pudding.

Once you start coming up with places you realise there could be several volumes of Fame By Chance. Donough O'Brien admits he could be kept busy for some time. "Just the other day I thought, hell, Kells!"

Bikini

After the unfortunate South Pacific island was the site of nuclear-bomb tests, the French swimsuit

designer Louis Reard named his two-piece the bikini because it was so "explosive".

Chihuahua

The Mexican city gave its name to

the tiny dog that enchanted the invading Aztecs.

Gotham

Batman's city is named after an English village whose inhabitants pretended to be mad to dissuade King John from building a hunting lodge there in the 13th century, as it could have been very expensive to have him as a regular visitor.

Hamburg

The small town in New York state gave its name to the hamburger when brothers Frank and Charles Menches had no pork for their sandwiches so instead sold cheap beef sprinkled with brown sugar at a local fair. "What is it?" asked a local. "Hamburger," replied Frank.

Route 66

The US road linked the populated midwest with isolated rural west, so becoming a fabled route for the adventurous.

Fame By Chance is published by Bene Factum, £14.99 in UK