In Roman times, the need for a canal at the Isthmus of Corinth was well known. In order to avoid sailing around the Peloponnesian peninsula, boats were being moved (dragged?) across the isthmus by taking them out of the water and hauling them up and over. As early as 700 B.C., plans were being made to cut through the rock and dirt to join the Gulf of Corinth with the Saronic Gulf in the Aegean Sea.
The Emperor Nero started work on the canal before his death in 68 A.D. He turned the first basket of dirt to kick off the effort. Unfortunately, work stopped after his death. The workforce consisted of 6,000 Jewish war prisoners.
Since the current canal is in the same place as Nero's, there is nothing left of his early efforts for us to see. The canal is over 6 kilometers long and was built between 1881 and 1893. It is only 21 meters wide, so only small ships can transit the canal. There have been a few problems with rock and dirt falling into the canal. In 1923, over 41,000 cubic meters fell into the canal and required closure of the canal for 2 years to clear it again. We stopped twice at the canal on our way to and from the Peloponnese while we were on an all-day bus tour. It was raining the first time, but the weather improved on the way back to Athens. I got some good pictures while standing on the bridge. It's a long way down (90+ meters) and I felt a little disoriented because of the way the bridge is constructed. It doesn't feel safe and it's a bit unnerving. But nothing blocks your view, so picture taking is great!