Corinth Canal, Greece

A 1960s view of a metre gauge steam train crossing the railway bridge over the Corinth Canal as a tug pulls a cargo ship through it.

The 6.4 km (4 mile) Corinth Canal connects the Gulf of Corinth with the Saronic Gulf in the Aegean Sea, cutting through the narrow Isthmus of Corinth. Because it separates the Peloponnesian peninsula from the Greek mainland, it effectively makes the former an island. It is entirely at sea level and uses no locks. It is only 21.3 metres (70 ft) wide at its base, making it impassable for most modern ships and has little transport importance.

Proposals for the canal dated from classical times and an unsuccessful effort was made to build it in the 1st century AD. Construction got underway in 1881 but was hampered by geological and financial problems that bankrupted the original builders. It was completed in 1893, but due to the canal's narrowness, navigational problems and periodic closures to repair landslips from its steep walls, it failed to attract the level of traffic anticipated by its operators. It is now used mainly for tourist traffic.

This aerial view shows how narrow the isthmus is at this point (aroundgreece.com)