Modern-day Shrewsbury may look nothing like the Shrewsbury of the Middle Ages, but a site on the outskirts of Budapest is its spitting-image. In the grounds of Foti Studios, the former aircraft hangar which has become the epicentre of the small but perfectly formed Hungarian film industry, Central have painstakingly built a replica medieval village. On a bright sunny day in September, I am taken back in time and given a guided tour of the set by Stephen Smallwood, the producer.
As we set out towards the formidable stockade that protects "Shrewsbury", Smallwood gets all proprietorial. "I feel like an estate agent," he laughs, "telling you the place has had one careful, pious owner." A cluster of little huts stands by the drawbridge outside the city gates, strategically placed to block out the electricity pylons and overhead railway cables. Filming has to stop every half an hour to allow the Budapest Express to go by, although that is not as disruptive as the farmers on tractors in a neighbouring field, the microlight aircraft overhead or the noise from the nearby Hongaroring during the Hungarian Grand Prix.
The city walls are made from thousands of tons-worth of timber imported from Russia - "I don't think Greenpeace would approve," Smallwood observes - and they make for an imposing facade. They contain 35 meticulously recreated medieval buildings, including the monks' refectory, infirmary, mill and cloisters. To the untrained eye, it looks highly authentic. Variety magazine was fooled, too. According to Smallwood, "In an otherwise wholly contemptuous review, they said that 'the English countryside has never looked so good.' "
All this, of course, costs big bucks. Each episode of Cadfael weighs in at a cool pounds 1m - but that is monastic compared to what it would have cost if shot in England. "It was impossible. We looked at the possibility of shooting in Shrewsbury," Smallwood says, "but it is a traffic island now. The original abbey has the A5 running through it, and the 12th-century buildings have many trappings of the more recent past. It's unfeasible - unless you're Kevin Costner with a $40m feature-film budget."
Smallwood did a recce of Poland for locations. "That was cheaper, but the infrastructure is so bad, I wouldn't have been able to persuade anyone to return there."
So Hungary it was. For all their unfathomability to Western Europeans, the locals are welcoming. Katalin Baranyi, a Hungarian teacher of English who is working as an interpreter for the wardrobe department on Cadfael, explains why. "Money talks - that's a Hungarian expression as well. But there's no bad feeling at all about the British coming over here. Under the old regime five or six years ago, the film industry was state-owned and got big budgets to make 20 films a year. Now the industry has been privatised, and the state doesn't put aside any money for making films. Unemployment is very high, 90 per cent of people live below the poverty line. We feel lucky when we find a foreign production company that wants to work here. We don't feel exploited." The only thing she feels hard- done-by about is the fact that Cadfael is not shown on Hungarian television..
The crew have had the odd problem with supplies; with the language barrier; with recalcitrant oxen and dancing bears; and with the weather. Apart from that, the filming has gone smoothly. Smallwood even nurtures the dream that the set could become "the Coronation Street of Hungary".
If Cadfael continues to grab ratings, then there are about 20 novels still to be filmed. Smallwood rubs his hands with delight. "There's no limit to the amount of murder and mayhem in 12th-century England," he cackles.
n 'Cadfael' will be shown on ITV on Boxing Day