Otumba or Otumba de Gómez Farías is a town and municipal seat of the municipality of Otumba located in the northeast of the State of Mexico, just northeast of Mexico City. Historically, this area is best known as the site of the Battle of Otumba and as an important crossroads during the colonial period where incoming viceroys ceremoniously were handed power by their predecessors. Today, it is a rural municipality undergoing changes as urbanization arrives here from the Mexico City area. However, one element from the past that is still remembered is that of burros or donkeys. During the colonial period, Otumba was an important market for the animals, and they are still culturally important. Each year, the municipality sponsors a Feria de Burros or Donkey Fair, where the animals star in fashion shows, costume contests, and races. There is also a donkey sanctuary for unwanted animals.

The State of Mexico, officially just Mexico, is one of the 32 federal entities of the United Mexican States. Commonly known as Edomex to distinguish it from the name of the whole country, it is the most populous, as well as the most densely populated, state in the country.