These two curiosities form an oddly appropriate pair. Both are among the largest of their kind in the world, and neither has ever worked. The 40-ton Tsar Cannon, built during the reign of Ivan the Terrible's imbecilic son Fyodor in 1586, possesses a barrel in excess of five meters long and a calibre of 890 mm. The gun should in theory have been capable of smiting foolish attackers with projectiles the size of wine casks. As if the cannon's sheer size were not inspiring enough, the barrel and carriage are adorned with a relief of the redoubtable Fyodor as well as a scene in which a fierce Russian lion devastates a snake symbolizing Russia's enemies.

The two hundred ton Tsar Bell, though the largest in the world, was never successfully completed, much less rung. A smaller predecessor (weighing in at a mere 130 tons) was built in the middle of the 17th century but was destroyed in the Moscow fire of 1701. Three decades later the Empress Anna ordered the fragments to be recast into a much larger bell, but the resultant wonder cracked in 1737 after having fallen into its casting pit. Another century passed before the bell was lifted and set in its present location. Beside the bell lies a small eleven-ton scrap that fell from the bell during its excavation.