Sir Alex Ferguson could scarcely believe the noise in the San Siro three weeks ago. "For the first 15 minutes I was feeling in shock, really in shock, because the atmosphere was unbelievable," he said. "That, coupled with the noise when they scored, it certainly unnerved me, and it unnerved my players." It's true. Serie A may have been toppled by the Premier League and Spain's Primera Liga as the best in the world, but the atmosphere for a big games in Italy easily exceeds those in England and Iberia. United under Ferguson have played in those seething Italian cauldrons against Roma, Fiorentina, Milan, Juventus and Internazionale. The sound level was always louder than bombs, the colours and choreography breathtaking. The 4,000 travelling United fans in northern Italy were placed high on the third tier. Loud enough for David Beckham to thrice acknowledge the 'There's only one David Beckham' chants, Reds otherwise struggled to be heard above the din of the home support. I met some of the Milan fans who had led the ultra life before the first leg in Italy and they explained how it works. Ticket prices are far cheaper than in England. It costs ?17 to sit (though most stand) on the curva behind the goal for a league game, ?20 for a big European game. That's less than half the price United fans will pay tonight for an equivalent seat. Under-7s pay ?2 to watch Milan, while away fans are charged ?14 in the league, ?20 in the Champions League. Milan's a rich city, but people of all ages and classes can afford to see their team. Tickets in Milan's best seats are far more expensive than at Old Trafford - the rich pay up, so that the poor pay less. Log on this evening to catch our live blog on the United v Milan game The Ultras are the hardcore and their culture is a major factor in creating the brilliant atmosphere. Ultra groups are well-organised, expending significant amounts of energy making huge flags, wordy banners or giant collages. They distribute their own match tickets so that the loudest fans are together, provide away travel and merchandise. Fans are inside the stadium three hours before matches building the tension, putting on a show that is never allowed to flag. In contrast to England where the songs tend to be spontaneous, Milan's songs are led by chorus leaders who spend the match with their backs to the pitch, bellowing through loudhailers. "The thing I can't understand about the English fans," explained one, "is that you travel in great numbers, drink and make noise before the game in the bars and streets, but then go quiet during the match when the team need the support." Maybe it's just the beer wearing off. Despite the crowd demographic changing and higher ticket prices, Old Trafford can still be a magical experience for big European nights. Travelling Catalans still talk about the `wall of noise' at Old Trafford for the 2008 Champions League semi-final. The Italian grass isn't always greener. The Ultras enjoy a love-hate relationship with officialdom who admire their support, but detest their independence and anarchy. At a higher level, the Italian government, worried by football hooliganism and several high-profile deaths, plans to introduce identity cards for travelling fans. The politics tend to be extreme and attendances have slipped because families don't feel safe. These are all serious issues which need addressing, but hopefully not at the expense of the spectacle which makes watching a big game in Italy such a rich experience, even when the home side loses. What do you think? Have your say.