The Conrinthian Canal connects the Gulf of Corinth with the Aegean Sea. It separates the Peloponnesus peninsula from the Greek mainland and therefore effectively makes it an island.

The canal is 6.3 km in length and was built between 1881 and 1893. It saves the 400 km long journey around the Peloponnesus for smaller ships, but since it is only 21 m wide, it is too narrow for modern ocean freighters. The canal is nowadays mostly used by touristic ships; 11.000 ships per year are travelling through the waterway.

The first attempt to build a canal at the place was carried out in 67 by the Roman emperor Nero, who ordered 6000 slaves to dig with spades. In the following year Nero died, and his successor Galba abandoned the project, since it appeared too expensive to him.