Big gub

War History Online has an article about a really big gub:

Schwerer Gustav was the name of a German eighty-centimeter railway gun. It was developed in the late 1930s by Krupp as siege artillery for the explicit purpose of destroying the main forts of the French Maginot Line, the strongest fortifications then in existence.
The fully assembled gun weighed over a thousand tons, and could fire shells weighing seven tons to a range of fifty kilometers. The gun was designed in preparation for the Battle of France, but was not ready for action when the battle began and, in any case, the Wehrmacht’s Blitzkrieg offensive through Belgium rapidly outflanked and isolated the Maginot Line’s static defenses, forcing them to surrender uneventfully and making their destruction unnecessary.
Gustav was later employed in the Soviet Union at the siege of Sevastopol during Operation Barbarossa where, among other things, it destroyed a munitions depot buried in the bedrock under a bay. The gun was moved to Leningrad, and may have been intended to be used during the Warsaw Uprising like other German heavy siege pieces, but the rebellion was crushed before it could be prepared to fire. Gustav was destroyed near the end of 1945 to avoid capture by the Red Army.
It was the largest-caliber rifled weapon ever used in combat, the heaviest mobile artillery piece ever built in terms of overall weight, and fired the heaviest shells of any artillery piece. It is only surpassed in calibre by the British Mallet’s Mortar and the American Little David mortar (both 36 inch).

Rico says now that's a gub...