The Greek historian Pausanias has reported that the ancient coastal-Peloponnesus city of Helice sank into the Corinthian Gulf during an earthquake in 373 B.C. A deductive approach to the present-day search has been made difficult by changes in the location of such local landmarks as braided-rivers and the shoreline. In order to more closely delineate the city's probable site, a geologic investigation of the region has been undertaken. Four onshore bore-holes provide a cross-section ranging from a hillslope on the south, across a central coastal plain, to delta-beach stratigraphy on the north. Three offshore bore-holes reveal a double sequence of beach gravel each overlain by fossiliferous marine silt. Based on radiocarbon dating of the contained fossils, it is hypothesized that a slump plane lies somewhere between these two groups of holes. While Helice may or may not be found for some time to come, the present investigation represents an effort to draw quantitative limits upon its hidden location.