If only this would have been the topic for last month.

Near Guilin in China there is a cave named "Red Flute Cave".
Its overwhelmingly huge and has the most impressive stalagmite and stalactite formations I have seen till today. And here the clou: They decided to light it with colored lights, and It looks just incredibly amazing.





The best thing: The guide doesn't push you trough, you are free to roam around.