Modlin Fortress (Polish Twierdza Modlin) is a 200 years old fortification phenomenon which can be compared in the European scope only with the Fortress of Verdun.
Started by Napoleon in 1807, the fortress is settled on a picturesque slope upon the Narew and Vistula rivers mouth.
The Modlin Fortress is Poland's biggest and most important monument of military engineering and fortification architecture. It is also the longest building in Europe measuring up to 2,5 km.