The Shadow Fold is the most dangerous of the biomes.
A dark fog creeps in, taking away much of the player's vision and the sounds of domestic blocks and mobs are dampened.
Barely visible rifts going down into the void every few steps increases the danger and difficulty even more.
To contrast this, small glowing particles rise slowly from the ground.
The islands are plain and rugged with twisting rifts that lead all the way into the void.