Back to genuine castles:
Savonlinna Castle:
Best looking castle in Finland. A late 15th Century castle with 18th Century bastions built on it's side.
Now here are two gems!
Castles of the West and East confronting each other: The Hermann Castle in Estonia (on the left) looking at the Ivanogorod Castle (on the right) in Russia. Still where the divide between the East and the West goes. The Narva river in between. This place has seen a lot of important battles. In 1700 between the Swedes and the Russians and in 1944 between the Germans and the Soviets.
Hermann Castle, Narva, Estonia:
German soldiers crossing into Russia from Estonia during Operation Barbarossa, behind the Ivanogorod Castle:
German soldiers on the defence at the same place in 1944 during the battle of Narwa:
American Airborne troops from the 173th posing on the Estonian-Russian border with Ivanogorod Castle and Russia behind them:

Still a flashpoint...