Corinth Channel map of the Corinth Isthmus
The Gulf of Corinth (Greek: Korinthiakόs Kόlpos) is a deep inlet of the Ionian Sea separating the Peloponnese from the mainland of Greece. Shipping routes between the Greek commercial port of Piraeus to western Greece at Adriatic Sea through the Corinth Cannal pass along this gulf. The dimensions of the Gulf are approximately 105 km long and 30 km wide with a basement depth of 3 km at its center. The modern 'Rio-Antirio' bridge (6 km) connects the Western Peloponnese with the Western Central Greece.
-- The Corinth Cannal (Greek: Dhioryga tis Korinthou) is a artificial cannal that connects the Gulf of Corinth with the Saronic Gulf in the Aegean Sea, separating the Peloponnese from the Greek mainland, arguably making the peninsula an island. Construction started in 1881, completed in 1893. An abortive effort was made to build it in the 1st century CE.