I Fell into the Underworld, and Now I Can’t Get Out

The Protagonist Creates Mazes, Dungeons, and Instances for the World to Conquer

I want to read something like "This World's Dungeons Are Far Too Plain". Something similar, where the protagonist creates a maze, dungeon, or instance in the real world, which other people discover and then try to conquer.

Apocalypse, System, Natural Disasters, Farming, No Zombies

Looking for pure survival stories about end-of-the-world disasters, where people build shelters underground.

Post-Apocalyptic Stories About Farming in Bunkers, Air-Raid Shelters, and Underground Cities

Apocalypse-era survival and farming stories about building bunkers, air-raid shelters, underground cities, and the like.

Recommendations for Treasure-Hunting and Exploration Novels

Fantasy Novels About Lords Building Dungeons