Lava lake

A lava lake is a small, widespread, naturally-generated terrain feature that contains a volume of lava.

Description
Lava lakes are shallow and often small bodies of liquid that generate above Y=0. Lava lakes found at the surface are surrounded by stone, which can be replaced by blobs of blocks such as dirt, gravel, and coal ore.

Lava lakes generate with a small air pocket above them, which may result in floating sand, floating snow cover, or even floating trees above. Lava lakes may cause trees to burn away.

Generation
Lava lakes are rare on the surface but often found in caves, and replace blocks around them with stone.

Lakes that attempt to spawn in midair are instead lowered down to the highest solid terrain below them. Superflat worlds with them enabled have many more lakes if the top is at a lower level than worlds that are tall.

$$, the air pockets above lakes are generated with cave air instead of normal air. This is true even for lakes that are exposed to the open sky.

Dungeons are able to generate attached to lakes.

Gallery
Lago de lava 湖