The existence of the Potidea Canal dates back to the 1st century AD. BC, while according to some sources it was opened by Kassandros in 315 BC, when at the site of ancient Potidea built Kassandria to facilitate navigation between Thermaikos Gulf and Toroneos and at the same time to fortify its city. The canal is 1.250 m long, 40 m wide and 8 m deep. During the Byzantine era, the area was called Doors and so is still called by the Halkidians. Along the canal there was a wall of towers at intervals, which secured even more from the land of Kassandra. The wall stretched in a nearly straight line, approximately 1,200 m long, from Thermaikos to Toronaios Bay. The canal had its current form in 1930 and in 1970 the bridge connecting the two shores was build.