Eliki was the most important town of ancient Achaia, from the years of its foundation until 373 BC, when it was destroyed by a devastating earthquake and tidal waves. The research efforts for the discovery of Eliki between the years 1950 and 1974 resulted in the location of the broader area of the lost town, which extends both on the land and into the sea. The recent systematic investigation, which started in 1988 in the sea and continues until today on the shore, has essentially led to the location of the site of ancient Eliki on the coastal plain. This undoubtedly proves the excellent results achieved by applying geophysical methods in archaeological research.