La Guelaguetza Festivity in Oaxaca Mexico

Las gradas del estadio y las sillas colocadas en la cancha de futbol estuvieron repletas. De acuerdo con los organizadores, al festejo acudieron aproximadamente 40 mil personas.

A Zapotec word signifying offering or offertory, Guelaguetza was the term used to describe the Oaxaca ceremony and celebration held each year to propitiate the gods in return for sufficient rain and a bountiful harvest.
More than three thousand years ago the indigenous peoples in what is now the state of Oaxaca began to cultivate plants to augment hunting, fishing and gathering. The most important of these was corn which formed the basis of their diet and, with the addition of tomatoes, beans, chiles and squash, evolved into a richly varied and delicious regional gastronomy. Thus the gods and goddesses involved with water and corn were vital among the hierarchy and the tribute to them was a lively and colorful celebration of the music, dance and products of the people.

The date comes from the time when the Mexicas conquered the Zapotecs, almost 500 years ago, in 1501. They brought their own form of worship, and their own gods. In July, they honored Centéotl, Corn Goddess; Xilonen, the Goddess of Tender Ears of Corn; and Huitzilopochtli, God of War. They built their temple on Bellavista Hill, right outside modern day Oaxaca.
Twenty years later, in 1521, the Spaniards conquered the Mexicas. They tore down the indigenous temple and built a church to Saint Carmen. But the people of the region continued to celebrate the old gods in July. So the missionaries changed the date of Saint Carmen's celebration to a Sunday in late July, and had a party for the locals on the following Monday. This became known as the Monday of the Hill celebration.