Lava

Difficulty: Class 4
A Lava Ravine ->This is the second level of the Deep Underground

This level obviously has more lava, about 3x more.

Also there's new blocks like Magma Stone and Fragmented Cobblestone while normal Cobblestone also spawns here.

This level is pretty small being only 50 blocks from top to bottom. In ravines you can sometimes see the top from the bottom of the ravine.

Trivia
Due to how much lava is in this level, almost no mobs spawn here

This level is very dangerous for obvious reasons and should be dug through as fast as possible

Bedrock can be found on the walls of this level

No new ores are introduced here