I’ve always had an interest in German railway guns. Massive beasts...
It was more a terror weapon than anything else. Sort of like “look, we can hit you from WAAAAAY over here, and you can’t do a damn thing about it.”
There was guy named Gerald Bull back in the 80s, if I recall correctly, he was contracted by Saddam Hussein to build a “super cannon” for them. He got... interrupted permanently ... before he could finish it.
https://en.wikipedia.org/wiki/Gerald_Bull
One of the things which seem almost impossible is how they made such massive guns. It boggles the mind.
Also such guns as the 18 inch ones on Yamato and Musashi. Also battleships with 16 inch thick armor plate and even thicker. How in the world did they do that?
I read fairly recently that there is not a single foundry in the world today capable of making battleship armor.