The Corinth Canal is a canal that connects the Gulf of Corinth with the Saronic Gulf in the Aegean Sea. The canal slices through the narrow Isthmus of Corinth and separates the Peloponnesian peninsula from the Greek mainland, thus effectively making the former an island. The builders dug the canal through the Isthmus at sea level; no locks are employed. The Corinth Canal is 4.0 miles (6.4 kilometres) in length and only 70 ft (21.3 metres) wide at its base, making it impassible for most modern ships. In modern times, the canal now has little economic importance.
The Corinth Canal was mooted in classical times and an abortive effort was made to build it in the 1st century AD. Construction finally got underway in 1881 but was hampered by geological and financial problems that saw the original builders going bankrupt. It was completed in 1893, but due to the canal's narrowness, navigational problems and periodic closures to repair landslips from its sheer walls, it failed to attract the level of traffic anticipated by its operators. It is now used mainly for tourist traffic.
Source = Wikipedia.org