Mukachevo, the Palanok Castle.

Mukachevo (or Mukacheve) has a population of about 80 thousands inhabitants and located in the Western Ukraine in the Transcarpathian area, near Uzhhorod and not far from the border with Slovakia and Hungary.
The Palanok castle - main attraction of Mukachevo, founded in 14th century. Really unconquerable fortress. For all its history it has never been conquered in a fair battle, one of the most fortified castle in the Europe. In 1782 castle has become a prison for political offenders.
Getting there : Plenty of trains with daily services from (to) Lviv, Kiev, Ivano-Frankivsk, Chernivtsi. Plenty of buses from the nearest towns of Transcarpathia (Uzhhorod, Khust, Rakhiv... etc.)