It has been nearly 2,000 years since the Roman Empire carved Via Emilia across Italy's northern plains. Its Legions used the road to streak across the top of the peninsula into Lombardy, France and Spain, and it worked so well that millions of people are still doing the same thing today.
To the untrained eye, this part of northern Italy is draped in a heavy, humid, white haze and dotted with small, fertile farms. But untrained eyes miss the stream of believers jumping off the A1 Autostrade, between Bologna and Milano, and turning onto Via Emilia. That's because Via Emilia is not just one of Italy's oldest continuously used roads, it's the funnel into the Valley of Motors, a 50-kilometre cluster of cavalli with the world's richest concentration of manufacturers making some of the world's most beautiful cars.
Ferraris, Lamborghinis, Maseratis and Paganis leave this valley to tease café strips and attack motorways all over the world. The motorcycle manufacturer Ducati also makes a home here, as do some of the most important road- and race-car museums in Italy. At other times, it has been home to Bugatti and the now-dormant brands de Tomaso and Stanguellini.
At the heart of it all is the rich, proud city of Modena. Blessed with astonishingly good culinary and artistic legacies and few visible tourists, Modena was the hometown of two of Italy's most famous citizens, Luciano Pavarotti and Enzo Ferrari. Even today, 20 years after his death, Ferrari's legend is larger and, some would argue, his music plays to an even bigger crowd.
Most of Modena's tourist traffic is on a pilgrimage to the Prancing Horse. The Italian sports car giant has the most successful Formula 1 team in history and owns a host of Le Mans 24-hour, Sebring 12-hour, Mille Migle and Targa Florio trophies. Founded in the 1928, Ferrari began life in the heart of Modena, but the factory was flattened by Allied bombers to stop it making aircraft parts. Wisely, Enzo Ferrari moved what was left to his quieter birthplace, Maranello.
There's a multi-storey car park on the original factory site (so nothing to see here), but it's not far from where Ferrari lived (a beautiful palazzo on the corner of Via Emilia and Viale Nicola Fabrizi, across the road from Pavarotti's favourite theatre and now hosting a bank on the ground floor). You can stroll three minutes from Enzo's house, up Via Emilia into the city, turn right on Corso Canal Grande and have a shave in the same barber's chair the great man used on every day of his working life.
From the centre of Modena, drive 22km along Via Giardini (another ancient Roman road) to see everything the Prancing Horse will allow you to see. Which, as many pilgrims find to their chagrin, is not much. Immediately before the motorway overpass on Maranello's outskirts is a right turn, which leads you to Montana. Michael Schumacher's favourite restaurant, Montana remains the favourite haunt for Ferrari's race and executive teams. The more famous Cavallino restaurant is across the road from the Ferrari factory gates. It's where Enzo and the late Canadian driver Gilles Villeneuve ate and it's stacked with even more historic memorabilia, but its food is nothing as good as Montana's.
Ferrari also built his own test track, which is around the corner from Montana. While F1 testing rules limit your chances of seeing an F1 car in action, the Fiorano circuit is in almost constant use for race- and road-car testing and driver training. It's only a few hundred metres from Fiorano to the main gates at Ferrari, but if you expect to tour the factory, you'll need to wave your paid car order proudly.
Tourists are inevitably disappointed by Ferrari, and the main reason is that, aside from the Ferrari factory shop across from the main gates, it shows little genuine interest in helping less-wealthy tourists understand the ups and downs of its journey.
Ferrari doesn't have a museum as such. Instead, it has the Galleria, which it designed as an active space. Some of its displays are excellent, such as a reproduction of Enzo's office and an F1 pit garage, but it's not really worth the entry ticket.
Most visitors come away with a lower, rather than enriched, impression of the brand, but they still stand an excellent chance of spying a secret Ferrari prototype road car testing on the public roads around Maranello.
The easiest of all the Valley brands to find, Maserati's famed Il Tridente (the Trident) dominates the skyline from Modena's tallest tower. Only four blocks from the city centre, Maserati has been here since it moved from Bologna (Neptune's Trident is that city's symbol) before the Second World War. The original Maserati building in Modena still stands to the right of the entry gate (and is home to senior engineers), next to the steel-and-glass masterpiece on the corner of Viale Ciro Menotti.
Behind them are the assembly buildings, which date back to the pre-war period. Maserati has a long history of ups and financial downs, though its outlook is brighter now than it's ever been. Unlike Ferrari, Maserati welcomes tourists into its ground-floor showroom, complete with a merchandising shop. And you can always see plenty of new Maseratis, because every car is taken on a 30km test loop before it's loaded for delivery. Stay long enough and you may even see one of the camouflaged prototypes for next year's convertible GranTurismo.
A car company built out of spite is always going to strut with attitude, and Lamborghini does attitude like no other car maker on Earth. Italian industrialist Ferruccio Lamborghini had owned a string of Ferrari road cars and tired of their reliability problems. He vociferously complained to Enzo Ferrari, who told him that if he thought he could build a better car, he was welcome to try.
So the tractor maker did, and Lamborghini arrived with a bang. Its Miura of 1968 wasn't the first Lamborghini, but it was the most appealing. Even now, it is universally regarded as one of the most beautiful 10 cars ever built and a stunned Ferrari could only look on. But, while it continued to churn out aggressive classics (the follow-up Countach is usually on the same lists), its financial viability was always scratchy. Sales of 250 cars a year might have guaranteed exclusivity, but never encouraged investment.
Audi took the brand over late last century and it has not looked back, but while Ferrari had room to grow, Lamborghini is on a thin sliver of land in Sant'Agata Bolognese, a small village 25km east of Modena.
Inside, though, is a wonderful, small museum, complete with multilingual guides who are trained and enthusiastic about helping people understand the brand's history. The two-level museum has every significant Lamborghini, including the Miura, the Countach and the world's first super SUV, the LM002. There are also picture boards across the walls to help with the history of each model and, upstairs, prototypes, concept cars, racing cars and even Lamborghini-powered Formula1cars.
Another highlight is the chance to dive into the factory to see the cars being pieced together by hand on two production lines run like a ballet of craftsmanship. The entire effect is that this brand, which exudes arrogance from its cars, is anything but arrogant to its customers and fans.
Horacio Pagani worked for Lamborghini as a carbon fibre genius before the Argentinian set up his own factory, between Lamborghini and Ferrari.
His team designed and built the astonishing Zonda, with every part crafted to an extraordinary degree and applauded even by the likes of Ferrari and Lamborghini.
Pagani builds less than 20 cars a year, but it is a flagship of craftsmanship. It sports a finely detailed carbon fibre chassis with a worked version of a Mercedes-Benz V12 for power.
Finding Pagani is easy (it's just off Via Emilia) and so is visiting it. From nothing to building the Zonda in a handful of years, Pagani's achievements are astonishing.
Ducati drifted to the fringes when the Japanese motorcycle wave hit in the 1970s, but has returned with an aggressive series of sports bikes and racetrack success.
Sitting on Bologna's outskirts, the factory and the museum nestle together in a convenient package.
Like Ferrari, Ducati's race teams and its road production are in the same area. This includes the bikes for reigning World Superbike champion, Troy Bayliss, and former MotoGP world champion, Casey Stoner.
In 1925, Modena's Fiat dealer, Francesco Stanguellini, founded a race team which won major races like the Targa Florio and took class wins in the Mille Migle 1,000-mile road race and the Sebring 12-Hour.
The family's museum contains its own cars as well as important race cars from Ferrari, Maserati and most of Italy's quirky race teams, plus trophies and memorabilia from before the Second World War all the way through to the 1980s.
It's an extremely professional setup with a slick bilingual website (www.stanguellini.it). It sits behind the family Fiat dealership, so it's easy to find. And entry is free.
Deep in one of its regular financial crises, Maserati had Modena worried. Long interwoven into local society as Modena's car company, there was a serious threat that the Maserati collection of historic race and road cars would be sold at auction and scattered around the world.
The community was in an uproar, so local businessman, Umberto Panini, stepped in and bought the collection and built an air-conditioned museum next to his home to house it all. It's still run by his son, Matteo, and includes everything from the 1936 Tipo 6CM Maserati to the T4 250cc motorbike. There are also Grand Prix-winning Formula 1 cars, most of the road car models and plenty of one-off prototypes, too.