The Corinth Canal was finally built in the late nineteenth century and created α new sea route by linking the Corinthian and Saronic Gulfs. Until that time, ships sailing between the Aegean and the Adriatic had had to circumnavigate the Peloponnese, adding about 185 nautical miles to their voyage. However, in antiquity the Greeks had devised α way of solving the problem of communications between the two seas. In the late seventh or early sixth century BC, the tyrants of Corinth constructed α paved road called the Diolkos which led from Schinous on the Saronic Gulf to Poseidonia on the Gulf of Corinth. The Dioikos was 3-3.5 m. wide, and it was paved with blocks of limestone set in α deep layer of sand and gravel. Along this ran the οlkos, α wheeled vehicle on which ships were borne overland from one side of the Isthmus to the other. Sections of the Diolkos can still be seen today; the deep parallel ruts in the road, 1.50 m. apart, are the marks left by the wheels of the olkos.

The possibility of digging α canal through the Isthmus had, of course, been considered by the ancient Greeks. The first to look into the matter was Periander, tyrant of Corinth, who drew up α plan for α canal in 602 BC. Subsequent planners included Demetrius Poliorcetes, Julius Caesar and Caligula. These plans were later adopted by Nero, who in 67 AD announced to the spectators at the Isthmian Games that he was going to join the two seas by digging α canal through the Isthmus; indeed, he went so far as to cut the first turf himself, with α golden pick, and to carry the first basket of earth on his back. But his plans came to nothing, as did those of Herodes Atticus, the Byzantines and the Venetians in later times. The canal we see today was built in 1882-1893 by Greek and French engineers using the most advanced machinery of the day. General supervision of the enormous undertaking was in the hands of General

Stepan Τϋpp, aide-de-camp to the King of Italy. The project was completed by the Greek Corinth Canal Company, whose president was Andreas Syngros.

The canal is 6,343 m. in length. It has α width of 24.60 m. at surface level and 21.30 m. at the sea-bed, and in some places its sides are 79 m. high.  The canal is crossed by road and railway bridges, while communications between Central Greece and the Peloponnese are also served by two 'ferries' in the form of submersible bridges, one at either end (Poseidonia and Isthmia).