This seaside village is located about 10 km east of Messolonghi, at the southwestern foothills of Mount Varassova, which rises impressively next to it. It owes its name to the cold spring that gushes from the mountain at this point. The spring is considered by some to be identified with that of Kallirrhoe, mentioned by Pausanias (Achaika VII, 21,1-5 and VIII, 24,9-10). It is possibly connected with an interesting mythological tradition, but there is no general agreement on the point as others place it in Kalydon, near the sanctuary of Artemis Laphria. According to the myth, Koressos, priest of the temple of Dionysus, fell in love with the virgin Kallirrhoe and sacrificed himself for her love. She then committed suicide out of shame at the spring, which was afterwards named after her.
The port of Kalydon, which was connected to the town by road, is located in Kryoneri. Due to the great geomorphological changes that have taken place, its traces have not been clearly identified to date, although there are reports of remains in the sea and a British Navy map of 1867 actually shows ruins under the water.
The remains that have been found in the area of Kryoneri indicate that the site enjoyed a great importance down the years, as it was close to the coast of the Peloponnese and offered relatively easy access by sea. On the western foothills of Mount Varassova the British archaeologist S. Benton had noted prehistoric buildings, while on the same side of the mountain tombs of Geometric and Hellenistic times have been found.
The importance of the area continued or was even enhanced in Roman times, since it seems to have been the starting point of a major land artery running from there to Nikopolis (near today’s Preveza). This hypothesis is further strengthened by the existence of a large seaside villa (villa maritima) with baths and of a basilica from the Early Byzantine period. The latter was investigated near the coast, sited at an old railway warehouse demolished in the 1980s; it probably belonged to a larger settlement. It was built on top of an older basilica, which itself had been constructed with more ancient material. The church was decorated with mosaic floors with floral and geometric designs and themes from the marine and animal worlds. Later, probably until the Middle Byzantine period, the site was abandoned and used as a cemetery. Perhaps due to barbarian raids, protection was now sought in more sheltered locations, such as Mount Varassova. The remains of the above-mentioned periods that have been discovered in the wider area of Kryoneri are not accessible today.
In the 19th century, Kryoneri was a transport hub for western Greece, since the railway line of the Northwestern Greece Railways started there: at 61.4 km long, it ran until Agrinio. It went out of business in 1975. The connection with the Peloponnese coast was made using the port and the steamer ‘Kalydon’, which reached Patras in about an hour and a quarter, provided there were favourable winds; it was often interrupted though by adverse weather conditions.