The city is built upon the exact spot of the ancient city of Aigio. According to the findings of the excavations, the area was first inhabited during the Paleolithic era and it has been under continuous habitation since 2000 B.C. During the invasion of Dorians (1100 B.C.) in the greek peninsula, Achaeans from several areas (especially Argolida) migrated to the area and founded important cities such as Aigio and Patras. Aigio itself has been the religious and political headquarters of the Achaeans, as well as the capital of the Achaean Sympoliteia (an archaic community between cities) around 276 B.C. After an extensive period of occupation from several cultures (Franks for approximately 200 years and Ottomans for another 400) and the peaceful migration of Albanian and Slavic population seeking for a better future, Aigio has been the first greek city to liberate from the Ottoman occupation (26th of March 1821) during the Greek Revolution.
Aigio nowadays is the second biggest in population city of the prefecture of Achaia. It is built by the sea. Areas of special tourist interest are the old section of the city (where one can still see elements of the typical architecture of the early 1900s) and the beach from the Railway Station (which in itself provides an example of Railway Architecture of the 1900s) to the church of Panayia Trypiti (Holy Mother of the Cave in a free translation, due to where the icon of the Holy Mother was discovered), the old storages of raisins (all now been internally transformed to luxurious cafés) and the old paper factory (providing a typical example of industrial architecture from the onset of the last century, now gradually being transformed into an academic institution). The findings from antiquity are not much and are rather scarce around the city. Towards the water storage of the city excavations revealed two rectangular buildings of 500 B.C and 400 B.C. respectively. The same excavation confirmed also the existence of a cemetery of the Classical era northwest of the same spot, while in the square of Psila Alonia (the central square of the city) tombs from the Mycenaean era were discovered. Towards the sea two more cemeteries (an Hellenistic and a Roman one) were also brought to light.
http://www.meteo.gr/cf_print.asp?city_id=110
http://aigio-home.tripod.com/id5.html
Here are a few links to websites that may interest you, about Aigio in particular and Greece in general.