I think it's real - Corinth Canal.

Although the canal saves the 700-kilometre (430 mi) journey around the Peloponnese, it is too narrow for modern ocean freighters, as it can accommodate ships only of a width up to 17.6 metres (58 ft) and draft up to 7.3 metres (24 ft). In October 2019, with over 900 passengers on board, a 22.5 metres (74 ft) wide and 195 metres (640 ft) long Fred. Olsen Cruise Lines cruise ship successfully traversed the canal to set a new record for longest ship to pass through the canal. Ships can pass through the canal only one convoy at a time on a one-way system. Larger ships have to be towed by tugs.[37] The canal is currently used mainly by tourist ships; around 11,000 ships per year travel through the waterway.[38]