Ancient Plevrona is mentioned for the first time by Homer, along with four other Aetolian cities, Calydon, Halkida, Olenos and Pylini, on the famous list of Greek ships that participated in the Trojan War. The location of Homerian (Mycenaean) Plevrona (Old Plevrona) is identified according to most scholars with the preserved ruins in Gyftokastro hills or Asfakovouni and Petrovouni near the present village of Nea Ydragogia of the Municipality of Messolonghi.

In the founding of New Plevrona stated the geographer Strabon, according to which the city was built immediately after 235/4 BC when Demetrius II of Macedon, also known as the Aetolian, destroyed the Old Plevrona. According to Strabon, the inhabitants founded a new city, the location of which coincides with the surviving ruins today in the “Castle of Kira-Rini.”

New Plevrona is located 5km Northwest of the city of Messolongi and occupies two hills at the southern foot of the mountain range of Arakynthos (Zygos). Built on a naturally fortified and strategically important location, it controlled both terrestrial highway linking southern Greece with Epirus and the straits between the Ionian Islands and Western Sterea. This is one of the largest in area cities in Aetolia with striking conservation of its walls. The strong wall has a total length of 2,360m. and includes eight visible gates, one small gate, thirty-six towers and eleven staircases.