Theater of Eretria, one of the oldest Greek theatres, is located inside the West Gate, in the north-west of the city and near the Temple of Dionysos. It was built between 400-500 BC and it has an estimated capacity of 3600. The auditorium had 11 rows, separated by 10 stairs, leading to the top part of the theater. The circular band moved north of 8 m and 3 m deep was constructed earlier. Nowadays, there are only a few but impressive remains of the scene, especially the underground passage leading to the orchestra center.
The port of Erétria is located at a distance of 11 miles west-northwest of cape Alivéri, in the bay that is formed right to the west of the gulf located between cape Manóli Mýti and islet Pezónisos. The south end of islet Pezónisos is also the southeast end of the port.