It sounds like a killer pub quiz question and probably is. Which city is the most popular setting for opera? The answer is Seville, where 128 operas have been set. The majority are entirely forgotten, but the city does provide the venue for six of the best-known and finest works in the repertory: Rossini's The Barber of Seville, Mozart's The Marriage of Figaro and Don Giovanni, Verdi's The Force of Destiny, Beethoven's Fidelio and Bizet's Carmen, still the most popular opera in the world.

Until now the Andalusian capital has done little to exploit this quirk of cultural history, but that is about to change. This September will see the inauguration of the Seville International Music Festival and its highlight will be nine performances of Carmen, not in the city's opera house, but in various unconventional venues around the city. The production is being organised by Opera on Original Site, whose previous successes include staging Puccini's Turandot at The Forbidden City in Beijing, Verdi's Aida at the temple of Luxor in Egypt and Verdi's Nabucco in Jerusalem.

The first acts - at the tobacco factory and the smugglers' camp in the mountains - will be staged on the immense terrace and gardens of the Plaza de España, a 19th-century imitation neo-Renaissance palace. After a two-hour break for dinner, the 8,000 opera-goers will be transported either by horse-drawn carriage (or more prosaically by coach and on foot) to the Plaza de Toros, a kilometre further up the Guadalquivir river. In the bullring they will join 5,000 Sevillianos (who will have been following the earlier action on giant screens) to watch the denouement.

Those who might suspect that there might be more than an element of dumbing-down in the inflation of Bizet's opera into such a mammoth spectacle should look at the quality of the artists involved. Heading the line-up of four Carmens is Angela Gheorghiu, one of the world's leading sopranos; the production is in the hands of the Oscar-winning film director Carlos Saura (who created an electrifying flamenco Carmen on film 20 years ago), assisted in lighting design by Vittorio Storaro, long-time director of photography on Bertolucci's films, as well as Apocalypse Now; musical direction is under the conductor Lorin Maazel, music director of the New York Philharmonic.

The fortnight of the festival will also include concerts by the New York Philharmonic and the Russian National Orchestra and recitals by such celebrated musicians as Rostropovich, Vengerov and Lang Lang.

As the organisers have to sell 100,000 tickets, considerable effort is going into marketing one-, two- and three-night packages that range from the easily affordable to the ultimate in corporate hedonism. Seville is a beautiful city with a great deal to recommend it, even without an opera to see.

If you enjoy yourself, you can return next year, when Fidelio will be performed in the immense ruins of the Roman amphitheatre in Italica, four miles north of Seville. And Don Giovanni is planned for 2006 to coincide with the 250th anniversary of Mozart's birth - this could be the start of a new annual arts fixture.

Seville International Music Festival: 2 -12 September; (00 34 954 50 66 10;