Corinth Canal Passage
 
The Corinth canal concept originated with Periander of Corinth in the 7th century BC. Daunted by its enormity, he chose to implement the Diolkos, a land trackway for transporting ships, instead.  Construction of a canal finally began under Roman Emperor Nero in 67 AD, using 6,000 slaves but ended with Nero’s death.  
 
Construction finally recommenced in 1881 but was hampered by geological and financial problems that bankrupted the original builders. It was completed two years later, but, due to the canal's narrowness, navigational problems, and periodic closures to repair landslides from its steep walls, it failed to attract the level of traffic expected by its operators.