Places that up to now have been relatively unknown have suddenly acquired huge popularity as thousands of tourists started to make pilgrimages there.

And other places that were already well known have seen their popularity increase and multiply.

In France, Scotland and Italy, tourism is now pushed by books or by films.

Take, for example, the Louvre, in Paris. In 2005 no less than 7,300,000 tourists visited it, a 600,000 increase in just one year from 2004’s 6,700,000.

According to the general administrator of the museum, Didier Selles, “Dan Brown (the author of the Da Vinci Code) is mainly to blame for this increase.”

And the museum, M. Selles adds, expects a further huge increase as from next spring when the film of the book, with Tom Hanks and Audrey Tatou, comes out. Scenes of the film were shot in part of the museum.

It has also been reported that the producers of the film are toying with the idea of having the first viewing of the film in Europe right inside the Louvre.

To cope with the huge increase in the number of visitors, the museum’s authorities have increased the number of people manning the entrance, so that no visitor has to wait more than 15 minutes. It has also opened new halls, thus reducing the number of closed halls from 25 per cent to just 13 per cent of the total.

The extraordinary success of the book has also inspired many tour operators (some have even been expressly created in view of this phenomenon) to organise tours with visits to cities and places mentioned in the book.

Thus, those who go to Paris, stay at the Ritz, where one of the protagonists of the book stays, and, after a visit to the Louvre, rent a Smart (as is done in the book), drive down the Champs-Elysées, visit the Gare Saint-Lazare and the Bois de Boulogne, not forgetting to visit the church full of secrets, Saint-Sulpice.

On then to London with tours to Fleet Street, the circular church The Temple, and King’s College in Cambridge.

And finally to Rosslyn Chapel, a splendid, mysterious gothic church in a mining village in Scotland where the book’s final surprise takes place. The church, until recently known to only a few, is one of the places where the protagonist searches for the Holy Grail.

The authorities responsible for this church, sensing what was coming, have created a well-displayed web site where one can read about the history of the chapel, with reference to what the book says, as well as a virtual shop where, without moving from home, one can buy numerous souvenirs linked to the book.

A one-day guided tour in Paris costs around e400 per person while a one-day tour in London costs around e300 for two persons. American visitors get the whole works and pay e3000 including the trans-Atlantic flight.

One can also visit the castle at Villette, another key site of the Dan Brown story, with a special prize for six days and five nights at the castle, a visit to the Denon wing of the Louvre, a lunch at the Ritz, a visit to Saint-Sulpice and an evening of readings from the book and a discussion, all for e4300 per person.

Not all are so enthusiastic about this development. The French, especially, are up in arms at this ‘depauperisation’ of their national history. “Is it for this that you have come to visit?” they ask incredulously. “Just to visit sites mentioned in a book of fiction?”

And the parish priest of Saint-Sulpice has engaged in a lost battle against the Dan Brown tourist hordes: “They come here asking me where the killing took place, and I continue telling them no such thing has happened here. Besides, all that is written in the book about this church is all wrong: from the description of the church’s architecture, to the paintings, the documents, the secret rituals that are supposedly carried out– there are no such things here!”

The same thing has also happened in Italy, with regard to another very popular book by Dan Brown, Angels and Demons, a story about the Vatican and many churches in Rome.

Just a few months after the book was published an “Official Tour of Angels and Demons” was created that takes visitors to tour the church of Santa Maria del Popolo, St Peter’s Square, the |Pantheon, Piazza della Minerva, Castel Sant’Angelo and Il Passetto del Borgo – all for e49 per person for four hours. One can also stay at the Hotel Bernini, another key site of the book and there is even a reduced price for schoolchildren – e35 per child.