Caves are a generated structure that tend to be found underground when Mining or in mountainous areas. Cave entrances can also be found on the surface and they are worth exploring as they can sometimes lead to abandoned mineshafts, dungeons, and even strongholds. There are three types of caves and there is the possibility of each of them yeilding valuable ore, even diamond ore if it is deep enough. While searching caves you must be careful as they could be inhabited by almost any type of hostile Mob since they provide protection from the sun. It is a good idea while exploring caves that you keep track of directions and use some breadcrumb indicator like always placing torches on one side of the cave, and marking new caves and/or explored caves. It is also a good idea to block off circular sub-caves.
Cave Types
Small Caves
These caves are shallow with dead ends and contain few ores.
Wormhole Caves
These caves are circular pits that extend deep and expose the entirety of the cave from the entrance.
Medium Caves
These cares are larger and contain more valuable ores than those of a small cave.
Large Caves
These caves go down very deep and will often yield very valuable ores.
The video below is one of the largest caves on Minecraft PE
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