The Man in Seat 61 has a detailed exploration of train routes from London to Athens, some including ferries.
Note that the state of basically all forms of transportation are in an indefinite state of flux due to the pandemic. It's impossible to say firmly whether cruise ferries from Italy to Greece will be running in December, and if they run, it's ...
There used to be Orient Express trains from London to Athens, but those stopped running... in 1962!
There are at the moment very limited international train services between Greece and the rest of the world. According to Wikipedia, the only trains running at the moment are:
Thessaloniki – Skopje – Belgrade
Thessaloniki – Sofia – Bucharest
Thessaloniki – ...
I have noticed before that Google maps blurs places on request from (local) governments where others do not blur.
One explanation is that Google maps was earlier and the request for blurring was not repeated with the other mapping services.
An other explanation is that the other map services did not comply with the request.
And a third is that while the area ...