To travel by train from Istanbul in Turkey to Sofia in Bulgaria, there is only one rail connection between both countries via the border crossing at Kapikule/Svilengrad.
Your travel route could be like that.1 Istanbul (Turkey) - Sofia (Bulgaria)
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The following links could be interesting for you.
|1||Istanbul (Turkey) - Sofia (Bulgaria)
|1A||Travelling from Istanbul (Turkey) to Sofia (Bulgaria)|
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