I just made a new world on creative that is only supposed to be a desert world but just look at the pics and you will see what i mean with the title.... And these wierd 'walls' are all over the place, even encircling a lake.
This is a customized world though. And just on this world i turned off caves and such and the whole world was really wierd. I also made the world only desert. The village was also wired because the houses were in the 'walls'.