The Corinth Canal is a canal that connects the Gulf of Corinth with the Saronic Gulf in the Aegean Sea. It cuts 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. It is 6.4 kilometres (4.0 mi) in length and only 21.3 metres (70 ft) wide at its base, making it unpassable for most modern ships. It now has little economic importance.