Τhe ancient theatre is one of the city?s most important monuments, although Pausanias does not refer to it in the 2nd cent. A.D. It is situated to the north of the acropolis, at a height of 350 m above sea level. The main theatre, the koilon, is horse-shoe shaped and provides ample view to the Corinthian Gulf. The construction of the theatre is dated to the first half of the 3rd cent. B.C. (around 280-250 B.C.), when the Second Achaean League, under which Achaean cities were reorganised, was established. The koilon was hewn out on the natural rock and whenever this was not available, the soil was cut in order to accommodate stone seats. The orchestra was also chiselled directly into the rock for its main part, while a channel was constructed on its wayside for the rainwater runoff. The scene of the Hellenistic period was a two storey building. A corridor, diazoma, divides the koilon in two parts and its spectator capacity is up to 3000 people, while its length reaches 30,70 m.