Diolkos

thumb|upright=1.2|The Isthmus of Corinth|Isthmus with the Canal of Corinth close to where the diolkos ran. thumb|upright=1.2|Strategic position of the Isthmus of Corinth between two seas.

The Diolkos (, from the Greek , "across", and , "portage machine") was a paved trackway near Corinth in Ancient Greece which enabled boats to be moved overland across the Isthmus of Corinth. The shortcut allowed ancient vessels to avoid the long and dangerous circumnavigation of the Peloponnese peninsula. The phrase "as fast as a Corinthian", penned by the comic playwright Aristophanes, indicates that the trackway was common knowledge and had acquired a reputation for swiftness.