Igloo

Igloos are structures that are naturally generated in snowy biomes. They are round structures constructed primarily of snow blocks.

Generation
Igloos naturally generate in the Ice Plains biome, but not in Ice Mountains or Ice Plains Spikes.

Structure
Igloos may spawn as a single room by itself, or with a basement. This is accessed by removing one of the carpets, revealing a previously hidden trapdoor. You will then see a very long ladder shaft, which leads down to the basement. It is comprised of stone bricks and variants, including monster stone brick. Within the basement are treasure chests, a cauldron, a brewing stand with potion of weakness and empty bottle, 2 red carpets, 2 spruce stairs a spruce wood slab, along with a priest villager and zombie priest villager trapped in iron bars.

Loot
In addition, a golden apple is found in some of the chests, always located in the central inventory slot.