In 373 BC a strong earthquake and the tidal waves that followed destroyed Eliki, the most important town of ancient Achaia in the Aigialeia region, and made it disappear under the waters of the Corinthian Bay. The neighbouring town of Voura, which sank into a chasm, was also razed by the same seismic phenomenon. Voura, however, was rebuilt by its citizens who happened to be away at the moment of destruction. Pausanias, in the second century AD, visited a littoral site called Eliki, east of Aigion, and wrote that the ruins of the ancient town were visible at the bottom of the sea. Later, the alluvial deposits of the nearby rivers covered Eliki’s ruins. Recent systematic research east of Aigion for the location and revelation of ancient Eliki brought to light new important data relevant to the ancient town and its broader region.