I'm aware that the game has dungeons, but I had never seen this before.
I was thinking on making an "excavation site" to figure it out myself, but then I notice something while going out from a near cave.. it goes all the way down. It is supposed to do that? 
I attached a couple of screenshots.
this is a surface entrance of a dungeon, sometimes they stick out of the ground like this 
It's basically a bug in the dungeon generation. They're supposed to be all underground with only entrances at ends of some caves. However sometimes these stick out of the ground a little. Personally I think it looks cool. I hope we do get a proper surface entrance someday.
also found a few down in hell too.
It's basically a bug in the dungeon generation. They're supposed to be all underground with only entrances at ends of some caves. However sometimes these stick out of the ground a little. Personally I think it looks cool. I hope we do get a proper surface entrance someday.
Yeah I like them too 
Then you break down a wall and go down the huge staircase to find a dungeon
It's basically a bug in the dungeon generation
Oh it's not exactly a bug We didn't restrict the dungeons to be underground only, so these things can actually happen (although it's very rare). That's why these parts slightly resemble a tower.
However, of course real surface entrances will also be added in the future 
I will definitely build a town close to it.. or around it!!
Thanks for your answers!
