The Corinth Canal slices through six kilometres of sedimentary limestone, carving the Isthmus of Corinth into an 80-metre chasm that separates the Peloponnese from mainland Greece. Construction began in 1881 and finished in 1893, though the concept haunted engineers for millennia. Roman emperor Nero initiated an excavation in 67 CE, deploying 6,000 Jewish prisoners to dig with picks; the project stalled after his death. French engineers revived the plan in 1869, then withdrew when cost projections doubled. Greek contractor Andreas Syngros finally secured financing from a French-Hungarian consortium, and dynamite crews blasted through 12 million cubic metres of rock over eleven years. The canal opened to shipping in July 1893, reducing the Athens-to-Brindisi voyage by 325 nautical miles. Today the waterway carries recreational vessels and small cruise ships, its vertical walls exposing horizontal strata laid down over three million years. The canal floor sits at sea level; no locks regulate the passage. Two submersible bridges at either end drop beneath the surface when ships approach, a solution installed after the original swing bridges corroded in the salt air. A railway bridge at the midpoint lifts on steel towers. The western mouth opens onto the Gulf of Corinth, the eastern onto the Saronic Gulf. Transit takes twelve minutes at the regulated four-knot speed limit. Corinth Canal boat tour from Athens departures typically pause at the eastern approach for photographs, then continue to Ancient Corinth, where the Temple of Apollo's seven surviving Doric columns date to 540 BCE. The Roman forum below the temple hill served as the administrative centre of the province of Achaea; its marble bema platform is the rostrum from which the Apostle Paul faced the proconsul Gallio in 51 CE, an episode recorded in Acts 18. Excavations begun by the American School of Classical Studies in 1896 uncovered the Peirene Fountain, the Lechaion Road's limestone paving, and the South Stoa's 33-shop colonnade. Many Corinth Canal boat tour from Athens tours extend south to Mycenae, where Agamemnon's Bronze Age citadel commands the Argive plain, or east to Nafplio, whose Venetian fortress overlooks the first capital of independent Greece. The canal remains a working navigation route, though its 21.4-metre beam restricts passage to vessels narrower than most modern cargo ships. Bungee-jumping operators now lease space on the road bridge at the midpoint, and a pedestrian walkway along the western embankment offers views straight down to the waterline. The isthmus cruise from Athens to the canal departs year-round, with morning sailings preferred for the angled light that illuminates the stratified cliff faces.