Tehuantepec is a city and municipality in the southeast of the Mexican state of Oaxaca. It is part of the Tehuantepec District in the west of the Istmo Region. The area was important in pre-Hispanic period as part of a trade route that connected Central America with what is now the center of Mexico. Later it became a secondary capital of the Zapotec dominion…Tehuantepec is a city and municipality in the southeast of the Mexican state of Oaxaca. It is part of the Tehuantepec District in the west of the Istmo Region. The area was important in pre-Hispanic period as part of a trade route that connected Central America with what is now the center of Mexico. Later it became a secondary capital of the Zapotec dominion, before it was conquered by the Spanish in the early 16th century.