The 42 cm Gamma Mörser as it was known in World War II or, originally, the 42 cm kurze Marinekanone L/16 (German for "short Naval gun with 16 caliber barrel") was a German siege howitzer. It was one in a series of super-heavy siege guns developed by Krupp before World War I. During the war, the gun was used to attack the Kaunas Fortress. The sole howitzer that survived World War I was used in World War II to attack the Maginot Line and the fortress of Sevastopol.