For decades, science fiction and fantasy writers have told stories about hidden underground kingdoms with their own vegetation and weather patterns. (Marvel Comics alone features maybe a couple dozen secret civilizations hiding beneath our feet.) There are even people who seriously believe that the middle of the Earth is hollow and full of weird creatures.

Now, according to the Mail, researchers have found something resembling those fictional underground worlds in China. And they've brought back some truly amazing pictures.

A team of expert cavers and photographers have been exploring the vast cave system in the Chongquing province of China and have taken the first-ever photographs of the natural wonder.

They were amazed to discover the entrance to the hidden Er Wang Dong cave system and were stunned when they managed to climb inside to see a space so large that it can contain a cloud.

If you're at all like me, this is the sort of thing that'll set off a whole month's worth of daydreams.