Stumbling, perhaps accidentally, onto some Mexican village fiesta may prove to be the highlight of your travels. Everywhere, from the remotest Indian village to the most sophisticated city suburb, will take at least one day off annually to devote to partying. Usually it's the local saint's day, but many fiestas have pre-Christian origins and any excuse - from harvest celebrations to the coming of the rains - will do.

Traditional dances and music form an essential part of almost every fiesta, and most include a procession behind some revered holy image or a more celebratory secular parade with fireworks. But the only rule is that no two will be quite the same. We've listed the most famous, spectacular or curious in this guide, but there are many others and certain times of year are fiesta time almost everywhere.

Carnival , the week before Lent, is celebrated throughout the Roman Catholic world, and is at its most exuberant in Latin America. It is the last week of taking one's pleasures before the forty- day abstinence of Lent, which lasts until Easter. Like Easter, its date is not fixed, but it generally falls in February or early March. Carnival is celebrated with costumes, parades, eating and dancing, most spectacularly in Veracruz and Mazatlán, and works its way up to a climax on the last day, Mardi Gras or Shrove Tuesday, when the only thing the inhabitants of certain other countries can manage is to toss the odd pancake.

The country's biggest holiday, however, is Semana Santa - Holy Week - beginning on Palm Sunday and continuing until the following Sunday, Easter Day. Still a deeply religious festival in Mexico, it celebrates the resurrection of Christ, and has also become an occasion to venerate the Virgin Mary, with processions bearing her image a hallmark of the celebrations. During Semana Santa, expect transport communications to be totally disrupted as virtually the whole country is on the move, visiting family and returning from the big city to their village of origin: you will need to plan ahead if travelling then. Many places close for the whole of Holy Week, and certainly from Thursday to Sunday.

Secular Independence Day (Sept 16) is in some ways more solemn than the religious festivals with their exuberant fervour. While Easter and Carnival are popular festivals, this one is more official, marking the historic day in 1810 when Manuel Hidalgo y Costilla issued the Grito (Cry of Independence) from his parish church in Dolores, now Dolores Hidalgo, Guanajuato, which is still the centre of commemoration today. You'll also find the day marked in the capital with mass recitation of the Grito in the zócalo, followed by fireworks, music and dancing.

The Day of the Dead is All Saints or All Souls' Day and its eve (Nov 1-2), when offerings are made to ancestors' souls, frequently with picnics and all-night vigils at their graves. People build shrines in their homes to honour their departed relatives, but it's the cemeteries to head for if you want to see the really spectacular stuff. Sweetmeats and papier-mâché statues of dressed up skeletons give the whole proceedings rather a gothic air.

Christmas is a major holiday, and again a time when people are on the move and transport booked solid for weeks ahead. Gringo influence nowadays is heavy, with Santa Claus and Christmas trees, but the Mexican festival remains distinct in many ways, with a much stronger religious element (virtually every home has a nativity crib). New Year is still largely an occasion to spend with family, the actual hour being celebrated with the eating of grapes. Presents are traditionally given on Twelfth Night or Epiphany (Jan 6), which is when the three Magi of the Bible arrived bearing gifts - though things are shifting into line with Yankee custom, and more and more people are exchanging gifts on December 25. One of the more bizarre Christmas events takes place at Oaxaca, where there is a public display of nativity cribs and other sculptures made of radishes.