Cervantes Festival: Nureyev, Bernstein, in a charming Mexican town

Each spring, during the last week in April and the first two weeks in May, the charming colonial city of Guanajuato hosts an extraordinary roster of internationally acclaimed performing artists under the banner of the International Cervantes Festival.

This year the festival will observe its 10th anniversary from April 23 to May 15 with an unusually gala and star-studded program, a nonstop series of performances of ballet, opera, theater, concerts, recitals, and folkloric ensembles. There will be appearances by Leonard Bernstein, conducting the Israel Philharmonic Orchestra; the Royal Philharmonic of London under the baton of Eric Leinsdorf; the National Theatre of Great Britain; Poland's famed Cricot 2 Theater, the Boston Ballet with a new production of ''Don Quixote,'' starring Rudolph Nureyev; Placido Domingo; Claudio Arrau; and folk troupes from the Philippines and Thailand, among other distinguished artists.

With picturesque plazas, narrow winding cobblestone streets, and colonial architecture, Guanajuato provides the ideal backdrop to festival events.

Located about 250 miles northwest of Mexico City, in a mountainous region that is rich in silver and gold ore, Guanajuato was the capital of Mexico's mining industry and one of the country's most prosperous communities during colonial times. The town was formally chartered by Philip V of Spain in 1741; many of Guanajuato's lovely old mansions, administrative buildings, and churches date from this year.

During the 33-year presidency of Porfirio Diaz around the turn of the century , Guanajuato became the focal point of modern Mexico's cultural life. In 1903, Teatro Juarez, an exquisite opera house, opened with a production of Verdi's ''Aida.'' Today, with the Cervantes Festival a strong contributing factor, Guanajuato continues to be one of the most culturally oriented of Mexico's 29 states. Teatro Juarez, with its eclectic and ornate architectural style, still dominates Guanajuato's main square, a small tree-lined and tiled plaza with an old-fashioned bandstand and lacy white wrought-iron benches.

Many of the festival's events are staged in Guanajuato's splendid churches and historical buildings. The Templo de la Compania, an architectural jewel built in 1747, with pink stone facade, neo-classical dome, majestic arcades, sculpted columns, is ideally suited to accommodate chamber music concerts and solo performances.

Folkloric dance and music ensembles perform in the large outdoor arena at the Alhondiga de Granadita, an old stone granary which was a fortified stronghold and the scene of an important battle during the War of Independence (1810-21).

In the evenings the delightful Plazuela San Roque, a small square with lovely houses and a beautiful old church, is a natural background for the festival's annual performances of Miguel de Cervantes's ''interludes,'' a series of satirical dramatic episodes. The highlight of the show is the dreamlike appearance of Cervantes, dressed as Don Quixote, entering on horseback, clip-clopping echoes resounding through the cobblestone streets. Performances of this freewheeling scenario began 29 years ago, when students from the University of Guanajuato took to the streets to entertain their town. This Guanajuato tradition became the seed for the International Cervantes Festival, inaugurated 10 years ago.

The festival has grown to its current size and status under the patronage of Carmen Romano de Lopez Portillo, wife of Mexican President Jose Lopez Portillo. The daily schedule includes from eight to 10 events, with the same performances presented for two consecutive days. Theaters and other performing spaces are within easy walking distance of each other.

Visitors to Guanajuato will wish to see the city's other attractions as well. Guanajuato is a wonderful walking city, nested in a shallow ravine, with mountains rising all around. The streets are, for the most part, narrow mazelike alleys that wind steeply up the mountain sides. These alleys, in some places no more than two or three feet wide, are lined with pastel-colored old houses, many with ornately carved wooden doors and handsome grillwork.

Guanajuato has few streets wide enough to accommodate autos. The most important of these is a four-mile-long subterranean road, a tunnel-like stone-paved thoroughfare that follows Guanajuato's riverbed and was originally constructed for use as a drainage sewer to protect the city's mines from flooding and landslide. Known as Calle Miguel Hidalgo, this street has uncovered areas where ancient balconies jut out overhead, subject to a most unusual point of view. In other places the road has an eerie and cavernous atmosphere. The road's carefully carved and well preserved arches are among the town's most popular attractions.

Mercado Hidalgo, Guanajuato's colorful and busy marketplace, is a short walk from Teatro Juarez. Merchants display local ceramics, woven articles, and a great diversity of fresh fruits and vegetables, herbs and spices, and local confections. Here bargaining is considered part of the art of buying.

Part of Guanajuato's charm is its remoteness. Tourists from the United States should fly to Mexico City. It is probably best to at least spend the night in Mexico City before continuing to Guanajuato, either by plane to the nearest airport at Leon (the flight takes an hour; so does the car ride from Leon to Guanajuato), or by chauffeured limousine or auto-rental (using the modern toll road 45D). The pleasant, scenic drive takes about four hours. American, Braniff, Eastern, Pan American, Western have flights from the US.

Guanajuato has several deluxe hotels, including the Real de Minas (telephone 2-14-60), Parador San Javier (telephone 2-06-26), and Castillo de Santa Cecilia (telephone 2-04-85), all of which offer appealing Mexican colonial decor with modern conveniences. They are all located on the outskirts of town. More centrally located and moderately priced are the Hosteria del Frayle (telephone 2 -11-79) and Hotel San Diego (telephone 2-13-00). Reservations for accommodations during the festival should be made now - as should tickets for festival events. For help in arranging for tickets, contact the local representative of the Mexican Government Tourist Office (located in most major cities); the main office is at 405 Park Avenue, New York NY 10022 (tel. 1-212-755-7212). Travelers to Mexico should be aware that the recent floating of the peso has brought prices down about 40 percent, making the country a better deal than ever.