Schwerer Gustav or Dora the German 80 cm railway gun

Krupp 80 cm Kanone Schwerer Gustav (Dora) Railway Gun

File:Schwerer Gustav Grenade.JPG - Wikimedia Commons

800mm (31.5 inch) German Artillery Dora

WT Live // Image by _PabloSniper_

Artillery Ammunition Comparison

Schwerer Gustav railway gun at Sevastopol - WW2 HistoryBook

80 cm Gustav Railway Gun

The Heavy Gustav, Hitler and generals inspecting the largest caliber rifled weapon ever used in combat, 1941 - Rare Historical Photos

A Nazi War Train Hauled the Biggest Gun Ever Made - Warrior Maven: Center for Military Modernization

A History Of War — The Schwerer Gustav was a German 800mm gun used