Malbork Castle, Poland
The Teutonic Order, a Catholic religious group founded as a military order, constructed the world's largest brick castle in Poland on the bank of the river Nogat in 1406. Now designated a UNESCO world heritage site, the fortified monastery, following multiple conservation efforts, stands as the world's largest castle measured by surface area. The Gothic-style brick walls surrounding the castle do little to hide the magnificent visual appeal of the castle's rising interior.