During the middle ages of my former world, fortresses and castle walls were considered the penultimate defenses of their time, but due to the eventual development of modern technology, they fell into disfavor and became nothing more than teardrops in history.
Aerial bombings, long-distance artillery, large-scale weapons of mass destruction, and iron tanks that could forcefully break through walls all caused these immovable barriers to become obsolete. That was why these historical places of legend, which had been so significant in wars of past, were opened to the public as scenic tourist spots in a relatively more peaceful era.
"The times will change, and with the emergence of new technology and species, the old maxims of battle will be nothing more than garbage. Even the strongest fortresses will become nothing more than scenic locations in the end."
