Strategically located at the narrowest, northernmost point of Kassandra peninsula, Nea Potidea (pop. 1,500) is about 70km southeast of Thessaloniki. At this point Kassandra is just a neck of land 1,200 meters wide. A 45 meter-wide canal was dug across this neck of land, connecting Toroneaos Bay with the Gulf of Thermi, saving boats narrow enough to make the passage the more than 100-kilometer trip circumnavigating Kassandra.

The canal has effectively turned Kassandra into an island. Its existence is first mentioned in writing by the ancient historian Strabo in the first century, AD, although it is several centuries older than even that ancient date.