5th
century
The radical renovation and expansion of the Dionysus’ theater started in the premature period. The displacement of the orchestra (which has become circular) happened to approach more the hill of Acropolis. Around the orchestra was built a sewage trench which flumed the water to southeast direction with the help of underground canal (euripus).
The earthy volume of the koilon at this time had a bigger pitch and was supported by two walls which held the soil.
On
the side of these walls, there were
entrances (parodoi) towards the
orchestra and the koilon.