When I created my default superflat world, I saw a 16x16 giant stone tower. It also included dirt and a bit of water. See screenshot. Can provide more info, didn't delete the world.
Linked issues
duplicates 1
Attachments
Comments 4
Oh I know why! I'd created a world with "x" name, then deleted it because I'd chosen the wrong type of world, and then created this one with the "x" name again!
41st Duplicate of MC-315, please use the search function to see if your bug has already been submitted. Currently over 54% of tickets are being closed as duplicate.
This is caused by chunks not being completely deleted when making a new world. This is actually a chunk from a default world.