The ancient theater in Eretria on the island of Euboea

Classical ancient Greek theaters were built outdoors. The natural slope of a mountain was used for the seating of the audience. The theater's orientation with respect to the cardinal directions was not random at that time. It was important that the sun did not shine directly in the eyes of the spectators, especially in the afternoon when performances took place.

In Eretria, there was no natural slope, so the builders likely excavated a cave in the ground to use the earth as a raised seating area for the audience. To prevent soil erosion, heavy retaining walls were constructed.

The theater's location seems ideal, as the audience faced directly south, allowing the stage to be well-lit throughout the day.

Dramatic performances originated from religious rituals. The presence of the residents was mandatory, and there had to be enough space in the auditorium for the entire community.

Usually, a temple stood near the theater - this was the case here as well. Very close by was a temple dedicated to Dionysus, from which a sacred image was brought to the theater on festive days.

The theater in Eretria dates back to the 4th century BC. It accommodated about 6,300 spectators. Its orchestra, the central part of the theater, had a diameter of 84 feet, which means it was larger than the one in the famous Epidauros.

The most interesting feature was the underground passage that ran from the skene, or backstage for the actors, to the center of the orchestra, measuring just over 12 meters in length. It was effectively used at that time, as actors could make entrances as if from beneath the earth, exemplified by the staging of Darius rising from the grave.

The building material was local Poros stone, which was used for the foundations. The passages were constructed from limestone.