But they are not dungeons.
Dungeons are a sickness, inflicted on the world by greedy deities who lust after sacrifice and struggle.
Dungeons are a virus, mutating and spreading, taking new shapes to combat the antibodies that may seek to destroy them or plunder their wealth.
Dungeons are alive and asexual, multiplying impossible cultures within themselves, all for the purpose of lengthening the pain deemed necessary for a worthy sacrifice.
Dungeons are where the gold grows.
Before the Edge Landers abandoned the Unknown World, they were voracious capitalists. Hoarders and marauders, they were notorious for their asset stripping culture, warring and empire building in order to collect mineral and material wealth. They felt confident to turn away only when they had gorged themselves already, when their coffers were bursting and they could spend generations building a new homeland of sparkling spires and glimmering streets.
But their greed and hubris did not go unnoticed by the Hungry Gods. Those vicious and venal divinities let the Edge Landers wallow in their perceived victory for a century or more. They watched as the Glittering Cities went up, shining beacons of man made decadence at the edge of the earth and the Abyss. They watched as the Ledge Hangers leaned over the Edge and learned of things that man should never learn. They saw the Lip Bound tie themselves to their hard won new lands with arrogant rituals of the earth and sea. They laughed as the Vergers imposed a policy of isolation, all the while patting themselves on the back at having won at the game of the world.
And then they sped up the oceans, twisted the tides, and pushed the onyx city of Abyssire over the Edge of the world.
The Hungry Gods want gold, and they want it great quantity. They know how the metal causes a madness of greed and lust within the mortal cultures, and so they want it unspent and thrown away, tossed into the Abyss with the right measure of pomp and ritual. They have already overseen the building of ridiculous temples in their own honour within the Glittering Cities, and were it not for their own absurd pleasure in the gaudy decadence of the Edge Landers architecture they would have demanded that the precious metals and priceless artefacts that are the building blocks of the cities be forfeited as well. But instead they have inflicted a terrible curse on the wider world, and tasked the Edge Landers with returning to places that they long ago abandoned in order to once again strip them dry.
Dungeons are self perpetuating hell holes, often deep underground, but at the very least out of sight of the sun - almost certainly to avoid the attentions of gods greater than their Hungry creators. Within them grow all the useless trinkets that man lusts after – gold and jewellery, silver and gemstones. The Hungry Gods like to seed them with powerful magic items and other useful prizes, in order to further increase the desire of those who are now forced to seek them out. But wherever the greatest rewards may be found, so too will the greatest dangers. Agents of the Hungry Gods have been placed within the dungeons, tasked with tailoring them with the most malicious and spiteful traps and pitfalls they can devise in order to lay low the gold hounds. The Hungry Gods demand sacrifice, and so within the dungeons they will receive it, all to lead on to further sacrifice as the Edge Landers weep whilst they commit fortunes to the aether. And so too have the dungeons been seeded with the base creatures and the low, the bloodthirsty and the terrifying, with the wicked tomfoolery of the goblin and the pitiless little mind of the bugbear, the pathetic cruelty of the kobold and the comedic savagery of the orc. One dungeon may bear the mark of a vindictive intellect, tailored with an eye to the ecosystem most likely to crush the resolve of any adventurers who get caught within it, a self contained cultural maelstrom of vehement intent. Another may be incomprehensible in it's manner and methods, peopled with such a mind boggling array of weird and horrific denizens so as to stun the senses of even the most hardened delver. It is rare that the Edge Landers know what they will find when they adventure into a dungeon, only that there will be these three things for sure – monsters, traps and treasure.