There are high-speed train projects for some provinces. Antalya, Aksaray and Nevşehir, Trabzon, Bayburt and Gümüşhane, especially in Bursa. There used to be a Bursa Mudanya train line, but now it does not. There is a historical train station in Ağrı Doğubeyazıt. It was built by the Russians, now it's a library. Here is the list of provinces without a railway:
25. Nevşehir (but there is a Kayseri Ankara railway that passes through the provincial borders.
Map of Turkey Fast Train
TCDD Railways Map (Detailed)
TCCD Railway Maps