Hidden Dungeons

Hidden Dungeons that no one knows how to enter. Legendary places full of extremely rare magical beasts, magic tools for power beyond measure and items that would be considered a rarity all over the world. It's said that Hidden Dungeons were given to people by the gods

To such a dungeon the entrance was opened. And an unexplored dungeon that the world is still unaware of, or just one with an as of yet unknown method of entry. There's always some kind of obstacle that prevents people from getting inside.

An entrance that doesn't open. No stairs to descend. Protection by an overwhelmingly strong magical creature. No knowledge on how to enter in the first place, and so on.

Precisely because of that the one to discover a way to enter is certain to be praised a hero. And that's an understatement! One time a certain Janton Jastal accidentally stumbled upon a stone that was required to enter a dungeon and just like that his country rewarded him with enough money to live multiple life times of bliss. That's how big of a deal Hidden Dungeons are.