Estonia: Rakvere
Rakvere is another old historic town in Estonia with a spectacularly massive 13th century castle on the hilltop and the town with a spiky 15th century church below it. The settlement probably existed from the 6th century, but it was the Danes who fortified it and built the fortress here to protect against Russia to the east. Denmark then sold the present day Estonia to the Livonian Order, who fortified this castle even further (again, against the Russians). Eventually, Russians took control of Rakvere in the middle of the 16th century, and then quickly lost it to a Swedish invasion. Polish-Lithuanian commonwealth captured the town next, then lost it to Sweden again, before Russia took control once more in 1720s. Every change of hands resulted in destruction and burning of the fortress and town. Although partially ruined, the fortress is still a stunning hilltop structure that you can explore in and out from all possible vantage points.