Mathematician John Graham-Cumming has put together a quirky guide for those interested in sights off science's beaten track, writes KARLIN LILLINGTON

FOR MOST tourists, a trip to the San Francisco Bay Area means a visit to the Golden Gate Bridge, a stroll up and down the hills, or a ride on a cable car.

But for a certain kind of traveller, Bay Area wanderlust is inspired by Mountain View’s Computer History Museum, or a walk in Palo Alto to gawk at the original garage in which Bill Hewlett and David Packard began one of the world’s most famous start-ups.

A visit to London means a short train journey to the second World War code-breaking headquarters at Bletchley Park. And a trip to Ireland means going to gaze on the plaque commissioned by Éamon de Valera by the Royal Canal walkway at Broombridge in Dublin, which marks the spot where 19th century mathematician William Rowan Hamilton came up with quaternary equations (quaternions) – complex equations that are used these days to create 3D effects in computer games and films.

In other words, the kind of travel itinerary that appeals to geeks.

Until now, the discerning geek traveller had to do a fair amount of research to unearth such interesting side trips. But no longer.

All these locations and more – 128 of them – are packed into John Graham-Cumming's The Geek Atlas, published this week by well-known technology publishers O'Reilly.

Why a geek atlas? “The idea came about because I wanted to buy this book, and couldn’t find it,” says Graham-Cumming.

More specifically, he was in Munich for work and, having some time on his hands, he popped into a tourist information office to see what sights might be nearby.

The office told him about the science-oriented Deutsches Museum (the German Museum of Masterpieces of Natural Science and Technology, site number 19 in the Geek Atlas) and off he went.

“It was simply amazing,” says Graham-Cumming. “I wondered, why didn’t I know about this? I thought there must be a book out there that would list this kind of place and went online to look for it and buy it.” To his astonishment, nothing of the sort existed.

So the security technology expert, cryptologist and mathematician who has written for the Guardian, Dr Dobb's Journaland other publications, thought perhaps he'd write such a guidebook himself.

“The next night in my hotel room, I came up with a list of about 70 places. Then I wrote a sample chapter, put together a proposal, and sent it to O’Reilly [his publishers]. And they said yes.”

For some readers, The Geek Atlaswill no doubt shape future travel plans. Scintillating geek destinations in 20 countries are listed, with details on how to get to them and what can be seen there. But the book is also for the armchair traveller who enjoys reading about science and technology.

“What I wanted to do was write the book I’d want to read, both the places but also the science behind the places,” says Graham-Cumming.

That was one of the biggest challenge of the book, he says, because he wrote about scientific fields very different from his own area of maths. “I had to sit down and learn, ‘Okay, what is the lymphatic system’. I also tried to have different levels of explanation. Some are quite deep.” Others – drug resistance in bacteria or how to clone a sheep, for example, which have been topics in the news – he wrote for a more general audience.

Choosing what to put into the atlas was his most daunting task: “I had to be pretty ruthless about what got in and what didn’t.”

He began with a list of some 300 spots, and that had to be whittled down to a manageable figure in order to keep the book portable.

He chose 128 (“a number I hope will have meaning for some readers – it’s a secret message for anyone who has ever done anything with binary”). He recognises many people will have their own recommendations for a list of geek must-sees, and a companion website – www.geekatlas.com – lets visitors post their choices and also add details, images and videos of their visits to these, or the spots listed in the book.

During many years of travelling he has visited most of the places he wrote about. Personal favourites include the Computer History Museum in Silicon Valley, the working model of Babbage’s Difference Engine in London’s Science Museum, the Joint (human) Genome Institute in Walnut Creek, California and the National Cryptological Museum in Maryland, which has a working second World War Enigma coding machine visitors can touch.

“If you haven’t typed on an Enigma machine if you’re a cryptologist, you haven’t lived,” he says.

Great unknowns: five geek sights you haven’t heard of

1. Experimental Breeder Reactor 1 near Arco, Idaho:

The first ever breeder reactor and in its parking lot there are two nuclear aircraft engines (that, happily, never got off the ground). And it’s free. If you are a nuclear tourist, this is the place to go: it features the first lightbulbs that were lit with nuclear power.

2. The International Latitude Observatory in Gaithersburg, Maryland:

If you’re an astronomer making accurate observations of the stars from an earthly observatory, knowing how Earth rotates is essential. This observatory was one of a chain that accurately followed Earth’s rotation and all its weird and wonderful wobbles.

3. The Fermat Museum in Beaumont-de-Lomange, France:

Pierre de Fermat is known for his Last Theorem which was only proved hundreds of years after his death. He lived in this market town in France, which is full of delicious local produce and a museum of his life and mathematics, with lots of mathematical games for people of all ages.

4. The nuclear bunker at The Greenbrier in West Virginia:

If the US were involved in a nuclear war, there needed to be a place for the entire US Congress to keep working. That place was underneath one of the most luxurious resorts in the US. The secret’s now out and the bunker is decommissioned and open to the public.

5. The Mendel Museum of Genetics in Brno, Czech Republic:

Gregor Mendel was the monk who figured out the fundamental laws of inheritance of traits by children from their parents by observing generation after generation of pea plants.
Years before genes were understood, Mendel had made observations and deductions that identified how traits are paired with recessive and dominate versions. KARLIN LILLINGTON

The Geek Atlas

is available from real and online bookshops. If bought in the UK at a shop or from Amazon.co.uk during the year, 50p goes to help save Bletchley Park.