Mungia lies 20 metres above sea level in an area full of open spaces, with a landscape of rolling hills; among these last are Gondramendi (217 m), Tallu (342 m) and Berreaga (366 m).

There are many small streams and underground springs, such as the Atxuri, Trobika, Lauromendi, Atebarri, or Mantzorriko Erreka, which are all tributaries of the Butroi river and provide water to the numerous fountains built in the town.

Although there are still traces which show that the area where Mungia stands today was inhabited in prehistoric times (there is a castro - a fortified place where an army used to camp - in Berreaga, and some steles of various ages have been found in neighbouring towns) the first documented reference we have dates back to the year 1051, when an abbot from Mungia ( Mome Munchiensis abba ) confirmed a gift from the Lord of Biscay to the Monastery of San Millán de la Cogolla.

At the beginning, Mungia, whose name comes from the Basque Mune - Ganean(which refers to its location at the edge of the Butroi river), was not much more than a tiny village with a very dispersed population.

At that time the church was the only focus of the community, but the settlement later began to acquire its own significance as a result of the presence of an abbot and of its location in a strategic pass between the interior of the feudal holding and the coast, primarily at Bermeo, which had begun to stand out as an export harbour.

By this means on 1 August 1376, under the Fueros of Logroño, the borough of Mungia was created in the centre of an anteiglesia (a village or municipal district specific to the Basque provinces) similar in extent to the Parish) of the same name.

Both belonged to the merindad of Uribe (an important and bigger borough which defended and governed all the towns and country houses inside its boundaries), and each had an autonomous municipality.

Economic activity was mainly based on farming, with a few mills located on the banks of the many streams which washed the area, as well as small craft workshops settled down in the borough.

The fountain which today lies in Beko Kale, in front of Arnaga, is the symbol of this unity under the motto "Biak bat eta biena" (Both only one and for both).