From Slavija bus to Belgrade airport, fly to Istanbul airport, then Metro to Istanbul. 4hrs 49min 89 €. From Slavija bus to Belgrade airport, fly to Sabiha Gokcen airport, Havatas Airport Shuttle Bus to Kadıköy, then ferry to Istanbul. 5hrs 42min 85 €. From Slavija bus to Belgrade, Plane to Skopje, Plane to Atatürk Havalimanı, then Metro to Aksaray. 5hrs 29min 269 €. From Belgrade Bus to Skopje, Bus to Otogar, then Metro to Aksaray. 19hrs 15min 87 €. From Beograd train to Sofia then train to Istanbul Sirkeci. 47hrs 32min 23 €. From Belgrade drive to Istanbul. 11hrs 45min 158 €.