Here we see a 21cm Morser 18 from the front, with the soldier to the right giving some idea of the massive scale of this gun.
This image came from the US War Department Technical Manual TM-E 30-451 Handbook on Germany Military Forces
How to cite this article:
Rickard, J (4 March 2023), 21cm Morser 18 from the front , http://www.historyofwar.org/Pictures/pictures_21cm_morser_18_front.html