Before the Corinth Canal there was another way from the Adriatic to the Aegean – across the Isthmus of Corinth on the Diolkos.
Although its a bit later than my sphere of interest – it started in around 600BCE and ran until the mid-first century CE – it is nevertheless a fascinating example of the effort that was put in to enabling trade (possibly).
There is a 20 minute animated video (shared by Kallioi Efkleidou on the Aegeanet message board) which shows features of the maritime voyage of a trade ship arriving at the Gulf of Corinth, crossing the Diolkos and ending up at Kenchreai before leaving for Cyprus. (There is also quite a bit on other technological marvels of the era) It was produced by the ASSOCIATION of ANCIENT GREEK TECHNOLOGY STUDIES (EMAET) & the Technical Chamber of Greece.
I’m not sure about some of the detail (were they still using ox hide copper ingots at this time, for instance, I don’t know?) but its a terrific piece of work.
There is a controversy over the preservation of the Diolkos with claims that excavated areas have not been conserved and are being damaged by today’s shipping (a Facebook group campaigns for its preservation) , debate over whether its primary purpose was military or trade and uncertainty over just how it was used. (Wikipedia).
As always the more we learn the more there is to learn!