Poland: Teutonic Castle of Malbork

Malbork castle was establish by the Teutonic Knight Order in 13th century as its headquarters (what later became Prussia). Known as Marienburg in German, the castle is biggest gothic fortification in Europe and the largest brick fort in the world – two rounds of walls protect three rounds of castles inside – lower, middle, and upper castles (the latter being a massive multi storied building. It took 230 years to build. While partially destroyed in WWII, it has since been restored and is one of the most outstanding UNESCO World Heritage sites in Europe.