Novogeorgievsk was seen as the "symbol of Russian rule in Poland." It would also mean the abandonment of Poland, which would compromise their ability to negotiate for more territory if the Allies won. Mikhail Alekseyev, the commander of the Polish sector, knew that to garrison the forts was a trap and the impregnability was an illusion. However, he was swayed by men of a higher social standing and left a garrison to defend Novogeorgievsk. The troops that he was able to spare were the remnants of the II. Siberian division, the 63rd division, and 58th division. To capture Novogeorgievsk, the Germans transferred General Hans Beseler who had successfully laid siege to the Belgian city of Antwerp early in the war. In a stroke of luck, his forces captured the chief engineer of Novogeorgievsk on the first day. The Siege of Novogeorgievsk lasted only a matter of days. When it fell, the Germans captured 1,600 guns and close to a million shells. Post World War I After the First World War Modlin became part of the Second Polish Republic and was modernized with modern bunkers, anti-tank and anti-aircraft equipment. Its main purpose was to provide cover for Warsaw from enemy attacks from the North. The fortress also housed several military barracks and military colleges for NCOs, including the Engineers Training Centre and the Armored Forces Officer Cadet School. Modlin fortress was the place of the Battle of Modlin during the German invasion of Poland in 1939. General Wiktor Thommée ensconced the Army of Łódź in the fortress after failing to fight his way back to Warsaw, and his was one of the last Polish military units to capitulate. Present day Some parts of the fortress are open to tourists. At the same time, the Polish military still has many facilities in the area and thus some redoubts are inaccessible. Some abandoned redoubts are not maintained and have deteriorated badly, with many metal elements having been pillaged for scrap. The Modlin airfield is located within the fortress area. It re-opened as the second civilian airport for the city of Warsaw in July 2012. In 2013 the Modlin Fortress was sold to private investors after being on the market for five years, but some key features such as the Tatar Tower and the White Tower must be preserved for the visiting public. Notes A misnomer as the Wyspa Szwedzka is in fact a