The Underdark — D&D’s vast underground dungeon — is widely seen as unrealistic. But, once again, Nature doesn’t give a shit about what we think is unrealistic.
Presenting the Er Wang Dong cave system in China, a cave “so enormous that it has its own weather system, complete with wispy clouds and lingering fog inside vast caverns”. Once again, copiously illustrated with photos.
And, oh yeah, Nature says “Suck it, pedants.”