JF Aus said;
Turkey, in the notorioius Kyber Pass for example, maybe.

Now I know you are not just a troll, but really incapable of anything.
Just in case I am wrong and you really are suffering from dementure
I would like to inform you that the Kyber pass is between Pakistan and
Afghanistan. Or is it India and Afghanista

Bazz,
Oh well it's late afternoon and it sounded like what I was thinking of.
What is the name of the treacherous mountain pass in Turkey?
Or am I incorrect about that also?

JF Aus,
I don't know of any difficult pass in Turkey. As far as I know it is
just a normal road between Turkey and Greece and between Turkey and
Bulgaria.
I know some went through Macedonia so they may have gone by road.

I see more have drowned going to the Greek Islands and also more were
drowned in the Mediterranean going from Lybia to Italy.
They need Tony Abbott over there, instead they got Sarah Hanson-Young !

Oh well some people are slow learners

Bazz,
I hasten to add I was in Greece in 1970 when an American was caught with drugs that later resulted in the film Midnight Express.
At the time those of us on the road were hearing about dangers in Turkey including high and very cold mountain passes. I think there were bandits in those years.
That's where in my memory in reply to you was coming from.
And my apologies for being incorrect about the Kyber Pass.

https://en.wikipedia.org/wiki/List_of_mountain_passes_in_Turkey

JF, I had a look at the link to passes, none of them are in the region
NW of Instanbul. Still I have never been in Turkey so do not have
first hand knowledge of the area.
The Orient Express used to go the Instanbul. So I presume the line still exists.