According to
Guinness World Records: "The Corinth Canal, Greece, opened in 1893, is 6.33 km (3.93 miles) long, 8 m (26 ft) deep and 24.6 m (81 ft) wide at the surface and has an extreme depth of cutting of 79 m (259 ft). It is still in use today."
From
Wikipedia: "Corinth, or Korinth is a city in Greece. In antiquity it was a city-state, on the Isthmus of Corinth, the narrow stretch of land that joins the Peloponnesus to the mainland of Greece. To the west of the isthmus lies the Gulf of Corinth, to the east lies the Saronic Gulf. Corinth is about 78 kilometres (48 mi) southwest of Athens. The isthmus, which was in ancient times traversed by hauling ships over the rocky ridge on sledges, is now cut by a canal."