In the Moscow Kremlin is an unusual monument is one of the most powerful guns of old, called the Tsar cannon.
The size of this gun is 5 meters, the barrel has a diameter of 98 inches.
On dule there is an inscription: "This gun was manufactured gun master Andrew Cohow. Weighs 2400 pounds". If you put the weight of the gun in the modern system of measures, it turns out that it weighs 40 tons.