Beginning as early as 600 B.C., the ancient Greeks created the Diolkos, an ambitious road partially paved with stone, that spanned across the entire Isthmus of Corinth. The overland route allowed sailors to avoid the perilous circumnavigation of the Peloponnese peninsula. One section of the road featured purposefully grooved tracks—considered among the earliest known railways in recorded history.
The Diolkos was "the first systematic attempt to facilitate the portage of merchandise and warships from the Saronic to the Corinthian Gulf and vice versa," says Dr. Georgios Spyropoulos, assistant director of the Corinthian Ephorate of Antiquities.
Ancient Corinth: A Bustling Center of Trade
Located on an isthmus west of Athens, ancient Corinth was a powerful, wealthy city that controlled commerce by land and sea. The region was home to the Isthmian Games, held in honor of the sea god Poseidon. Olive oil, wine, textiles, pottery and other forms of exotic trade flowed throughout the region.
South of the Corinth isthmus was Cape Maleas, which tore vessels to pieces and plunged sailors to their deaths. In Homer's Greek epic Odyssey, the heroic Odysseus tried to sail through these dangerous waters but was blown off path and ended up in the land of lotus-eaters. Rather than braving the treacherous southern route, some ancient travelers used the Diolkos, which bridged the 4-mile distance between Corinth’s primary western and eastern ports.
Centuries later, in A.D. 67, the Roman Emperor Nero attempted to build a canal between the Corinth’s ports using thousands of slaves, but the project was soon abandoned.
Construction of the modern (but narrow) Corinth Canal was started in 1882 and completed by 1893.
Discovery of the Diolkos
Starting in the late 1950s, archaeologist Nikolaos Verdelis excavated parts of the Diolkos and dated it to around 600 B.C. during the reign of Periander, the Second Tyrant of the Cypselid dynasty that ruled over ancient Corinth. One legend says Periander built the road instead of a canal because his priests warned "the anger of the two oceans at being mingled would result in the downfall of Corinth."
After ships approached the coast via the Gulf of Corinth, they "were hauled over a sloping stone-paved jetty, the west end of which was probably underwater, upon wooden rollers, before being hoisted onto the wheeled vehicle," says Spyropoulos. Many wagons were laden with heavy cargo, likely timber or marble, and pulled by animals.
The Diolkos varied from 15 to 20 feet wide and was paved with poros limestone. Some stone blocks were taken from abandoned monuments and archaic Greek letters were still visible. The Diolkos stretched for about 5 miles because it was built around the landscape to ensure a consistently mild inclination of less than 1.5 percent. No trace remains of the eastern portion and the exact terminus is unknown.
As the Diolkos curved inland, excavations revealed that the worn wheel ruts gave way to a unique railway, carefully and purposefully cut into the stone. "Verdelis [the archaeologist] was right to read these as cut grooves," says Dr. David Pettegrew, professor of history and archaeology at Messiah University. The grooves measured 5 feet wide and were clearly engineered to accommodate wheels.
The Diolkos was part of a larger road network meant to move people, ships, and cargo. Other rails existed in the ancient world, but they had a singular purpose, such as moving stone out of a quarry to a staging area, and so aren't considered a true precursor to modern railroads.
Warships Crossing the Isthmus
Most historians now believe ancient warships were not regularly moved overland via the Diolkos, but ancient texts suggest it was used at times in this way.
In the History of the Peloponnesian War, Greek historian Thucydides recounted the first Isthmus crossing in 412 B.C. when Spartans secretly moved their warships across "with all speed" towards Athens, rather than braving the treacherous sea voyage. Other ancient chroniclers, including Polybius, wrote about several more dramatic journeys over the centuries.
One such event occurred in 102 B.C. when Rome dispatched Marcus Antonius, the paternal grandfather of Mark Antony, to attack Cilician pirates. His fleet portaged across the Isthmus and sailed to Pamphylia to his eventual triumph.
Roman historian Cassius Dio wrote about Octavian's military maneuvers during the War of Actium in 30 B.C. and noted "because it was winter, he carried his ships across the isthmus" and returned "to Asia so quickly" that the feat startled Mark Antony and Cleopatra, for they "learned at one and the same time both of his departure and of his return."
The Greek government is restoring and protecting some sections of the Diolkos to prevent further wear and erosion. Ongoing excavations may yield further details about the ancient engineering feat and its uses.