Caves are randomly generated patches of air blocks (lava source blocks at layer 10 and below) in the underground, leaving exposed stone and other blocks generated with the terrain (such as mineral veins). They consist of a series of irregular tunnels branching off and winding in other directions, which may connect to the surface of the map creating natural entrances to the cave. In jungle biomes, vines generate in caves near the surface. Sand often will fall into caves generated near the surface of a desert or beach; craters in the sand will alert the player to caves below the surface.
Caves generate at any altitude up to Y-level 128. Caves can be quite deep, extending from the surface all the way to bedrock. They frequently intersect natural structures such as other caves, dungeons, ravines, and mineshafts. Because of low light levels, hostile mobs and bats often spawn in caves deep underground.
A cave can be classified into the following kinds of cave systems.
Hollows are highly cave-like structures that generate in biomes such as Extreme Hills. They are essentially overhangs that have been completely closed off and can be seen as the inverse of floating islands. These are extremely rare and usually have floors corresponding to the biome (most commonly grass).
Small caves are primarily located close to sea level and are unlikely to be linked to other caves. Because of their relative shallowness, they seldom contain anything more rare than small deposits of basic ores such as coal and iron. Such caves may have multiple entrances which are naturally lit by sunlight or moonlight. These type of caves almost always feature pools of water/lava within, likely caused by the generation of the water itself.
Medium-sized cave systems are commonly found within reach of other, often smaller caves, which are accessible via mining. These caves frequently contain large deposits of basic ores alongside small repositories of rarer materials - including lapis lazuli and gold. Such caves also regularly contain, at the very least, minor water or lava flows as well as the presence of dungeons.
These are large subterranean systems, found deep within the earth, often close to bedrock. They hold large deposits of essentially every known type of ore - with rarer materials, such as diamonds and emeralds, being found. Such systems contain a number of lakes of all types, as well as the presence of major lava and water flows.
During the terrain generation process, large symmetrical and cylindrical caves of various sizes can infrequently be created underground which often merge with other cave systems. These unusual type of caves vary from roughly 5 to 22 blocks in height, and from roughly 11 to over 30 blocks in width and/or length, though larger examples are quite rare. Although not particularly of interest, from a mining perspective, they may appear unnatural and irregular in comparison to the surrounding terrain. While the smallest rarely contain many ores, the largest can be quite useful for mining as their sheer surface area rivals that of a large ravine.
Ravines are tall, long cracks of air, usually measuring around 30 to 50 blocks in height, 84 to 112 blocks long and no more than 7 blocks wide. Ravines can have small ledges along the top. They can be found at levels 20 to 68, sometimes appearing on the world surface or underwater, forming canyons. They can go very deep underground, sometimes spawning slimes or exposing diamond ore. If they reach deep enough, they may also be floored by the lava lakes at level 11. In the Amplified world type, ravines can cut down from surface level all the way down to bedrock. Ravines can also be found in oceans or rivers having a waterfall from the river/ocean falling into them.
Ravines can connect to caves, dungeons, abandoned mineshafts, and any other generated structures. Due to the large surface area of their walls, ravines often have water and/or lava flowing down them (from springs in the walls, underground lakes, or even openings to the sea).
These caves have a large hole for an entrance and then spiral down, often cutting into coal and iron deposits. Rarely, these entrances can go nearly straight down, exposing rarer minerals.
These caves are often connected with the sea, and can be accessed from the sea. These act like underwater entrances to caves, often large ravines. When lit by lava, they allow the Player to see them from the surface of the ocean.
Found in every part of the world, underground water lakes are the most common type of lake. Water lakes may occur anywhere from a mere 1-20 blocks below the surface, all the way to bedrock.
These type of lakes are most often found in large caves deep underground, although they may rarely appear on the surface. Though lava lakes can be extremely dangerous, if you have a bucket of water on hand, dousing lava lakes can be a quick and easy method of obtaining obsidian.
|0.24_06||Caves are longer and more narrow.|
|The deeper underground you go, the bigger the caves are.|
|January 22, 2010||Caves are no longer filled with water as often.|
|June 16, 2010||Caves are now clustered instead of random.|
|June 17, 2010||Caves have 1–5 exits, enabling multiple escapes. Caves are now so clustered that a cave could be described as "Swiss cheese". More water and lava springs in caves. Tunnels have a wider variety of thickness. Gravel and dirt can now be found in caves.|
|1.0.3||Caves now have ambient noises such as moans and train whistles.|
|1.2.6||Pools of water and lava can now be found in caves.|
|1.2||Ores can now be found more often on the walls of caves.|
|1.4.2||12w38a||Bats added, and are the only passive mob to spawn in dark caves.|
|12w38b||New cave sounds added.|
|1.7.2||13w36a||Cave generation tweaked, making caves less dense and interconnected.|
|1.8||14w02a||Caves now generate with granite, diorite, and andesite below Y:80, in a similar abundance to gravel or dirt.|
|14w20a||Caves now generate on the surface of desert, mesa, mega taiga and mushroom biomes.|
|14w32a||Caves surfacing in mesa biomes now generate with red sandstone rather than sandstone.|
|1.10||16w20a||Caves now no longer generate with sandstone in the ceiling, when they surface through sand of any type. The sand will instead show unstable sand particles, until it is disturbed.|
|Pocket Edition Alpha|
|0.9.0||build 1||Added caves.|
|TU1||CU1||1.0||Patch 1||Added caves.|
Issues relating to “Cave” are maintained on the issue tracker. Report issues there.
- Caves will often be overwritten by sand and sandstone, as well as other generated structures.
- Though ores are abundant in caves and often require little digging to get to, ore veins visible in the walls of the cave often contain little ore, as the cave cut through them when it was generated.
- Although caves generate in the Nether, they are generally not as of much interest as Overworld caves, since the Nether itself is essentially just a huge cave. Overworld caves give free tickets through the terrain exposing many ores, while the only ore of interest in the Nether can be found everywhere already. However, a secondary lava "sea" is not generated in the Nether as with Overworld caves, and as such Nether caves can reach exposed bedrock.
- Ambience, which are sounds that can be heard around and within dark caves.
- A guide to exploring caverns