Caves or caverns are naturally formed cavities in the stone layer of a map. Most caverns have tunnels branching off as catacombs and winding in all sorts of directions. They are often very deep and can go from the surface all the way to bedrock. Caverns are not ravines but will often lead into them. Because of the lack of any illumination, they will often have enemy mobs like skeletons, zombies, spiders and etc.
One should never go into a cavern without a good supply of any lighting and weapons. Leave all of the valuables back in a safe place on the surface. But if these valuables are from the cavern itself, make sure to have a chest to put them in.
Caverns are huge and can have numerous intersecting tunnels, making them easy to get lost in. Getting lost in a cavern can be very dangerous, since getting lost in a cavern for too long may easily drain your hunger, saturation, weapon and armor durability, leaving you hungry and vulnerable to attacks, both of which could cause your death.
There are many ways to find caverns.
- Exploring surface
- By exploring the surface of the map, there is a good chance that an exposed cavern can be found.
- Digging around might uncover caverns, but it is not easy as the map is (very) large. Choosing a random location and digging a tunnel straight down will intersect a cave system roughly 40% the time, but is not recommended since mining straight down may cause the player to fall in lava, a deep underground ravine, or a cave system full of mobs. A diagonal tunnel (downward staircase) takes 3 times as long to dig, but is much safer and can be traversed both ways. Make sure to look out for dripping water or lava above you as it hints at a lake or pool of lava. You can also find caves by quarrying on layer 10 and have your exploration much more profitable rather than only having cut through ore veins that contain less. Quarrying on layer 10 can get you diamonds and lava pools, as well.
- By following the source of ambience, or the sound of mobs coming from underground, there is a great chance to find a cavern. It's also useful to follow sound of water. Lava makes a sound as well, which can be useful in finding diamonds, since lava and diamonds can be found in the same layers underground.
- Dig down, place a piston and power it. Since pistons don't extend if there are 13+ blocks ahead of them, you can use pistons to find caves.
- The Nether
- Traveling to the Nether, going down roughly 20 to 30 blocks, along by at least 16 blocks, and creating a new portal will likely cause the new Overworld portal to spawn in a cavern since a portal is spawned in the nearest suitable space for the portal.
- Use 3rd party software (such as cartograph) to make maps of caves. This can easily lead the player to dungeons or caverns.
These are some of the recommended items the player should bring with themselves into caverns.
- Weapons - Because of a cavern's low light level, mobs such as zombies, spiders, skeletons, creepers and possibly other aggressive mobs will spawn on the dark areas of the cave, making exploration dangerous. It is recommended the player brings weapons such as swords or bows to fight off said mobs.
- Armor - As said before, lots of mobs spawn in caverns because of the low light level. Iron or higher tier armor may be needed when exploring caverns, so as to give the player better protection against mobs. Exploring without armor is very dangerous, as mobs can kill an unarmored player in just a few hits. Armor can also be enchanted to have Fire Protection (for lava and burning), Projectile Protection (for skeleton's arrows), Feather Falling (for falling damage), etc.
- Tools - Because of caverns being found at stone level, lots of ores such as iron, coal, gold, redstone, lapis lazuli, or on rare occasions, diamonds or emeralds, so it is recommended you bring pickaxes along with you to mine ores. A shovel is also helpful for digging gravel and dirt more quickly
- Lighting - Caverns can be and will be very dark. Be sure to bring along any source of illumination. Rather than bringing many stacks of torches, bring wood and coal to craft them as needed. Stacks of sticks and coal would take twice as much inventory space if crafted into torches. With a single stack of logs, you have enough wood for 2048 torches, and you can mine coal to craft more torches as you go. While jack o'lanterns aren't so easy to make in the field, they also can be used for marking directions in the cave by facing them in a certain direction. More advanced players might even bring glowstone.
- Food - Cavern exploration may take quite a long time, draining your hunger. Also with mobs spawning, and the fact that you can get lost may further help drain your hunger. Bring filling food such as cooked porkchop and cooked salmon if possible. Cakes can restore a lot of hunger, but will not fill hunger saturation and must be placed before eating.
- Optionally, any golden food, for instance, a golden apple, can give you status effects that can aid your survival, like regeneration and absorption.
- Optionally, a fishing rod, for fishing. Water can be found in caves, so it may not be much of a bother. However, fishing underground can be slow (no open-sky or rain bonuses), so it may take a while to catch a fish, especially a fish that is edible.
- Optionally, a bucket of milk can help remove any status effects inflicted on you, especially cave spider poison and witches.
- If the player runs out of food, and gets lost, they can use rotten flesh from zombies as an alternative. The player will usually get food poisoning; the trick here is that the duration doesn't accumulate, so if the player eats a lot of rotten flesh quickly, they can fill up their hunger bar, then tough out the food poisoning and end up with their hunger bar almost full (but no saturation).
- Log - Bringing in a stack of log will let players craft a variety of useful blocks in the field, without having to carry large numbers of all of them: Torches are the most usual, but players can also make a crafting table and then make such blocks as chests, ladders, fences and gates. Don't craft logs into planks or sticks until you need to; large quantities of either will take up more inventory slots than the original logs.
- Others - other items and blocks can help players to aid survival and reach any exploration goals, like a bed for instance.
- (Water) buckets - Empty buckets stack (while water or lava buckets don't), but the player will want to keep at least one bucket already filled with water. This is useful for turning lava into obsidian, allowing it to be safely walked on or mined. Note that there can still be lava below it though, and the water should keep flowing. This also useful for extinguishing themselves when on fire. Empty buckets can let the player move water or lava springs out of their way, or collect more water or lava for their own purposes.
- Blocks - A few stacks of cheap blocks, for instance, dirt or cobblestone, can help reach certain places of the caves.
- Compass - Sometimes when the player get completely lost, they can just simply dig up to the surface and use a compass to guide them home. It is only helpful if their house is near the world spawn or if the player has used the compass on a lodestone near their base.
It is surprisingly easy to get lost in caverns. Below are a number of methods the player can implement while exploring to prevent this, especially trail markers. The navigation tutorial has much more information about markers and other navigation methods. (Summary: Torches, wool, signs, blocks (which can be placed in "arrows", and especially jack o'lanterns.)
One fairly easy marker method is the "torch on the right" rule. While exploring a cave simply place torches on the right side of the wall as players go deeper in. This way, no matter how complicated and even intertwined the caves get, you can always find their way back because if the torch is on the left of a cave wall, that means they are heading towards the exit. Conversely, if it's on the right, it means they are heading deeper in.
Another tip is to use markings such as colored wool, or other blocks, to find where the player came from. The player can also put signs for further clarification, pointing to the direction in which they came from. Optionally, they can make an arrow shape with the blocks themselves.
Also, a player can place magenta glazed terracotta to place on the wall or floor as it has an arrow pattern on it. This can help show which way is the exit.
While it will not help the player in navigating the cave itself, it may be wise to bring a map with them into a large cave, should the player get lost and need to dig the way out. Note that most caves occupy less area horizontally than they might seem, but interconnected caves and mineshafts can sprawl over huge distances. The player might well map some new surface as the player is exploring underground, but the cave itself will not be mapped.
Caves can be very dangerous - the light level is dark enough for monsters to spawn, gravel is very common, which could suffocate the player, and the player will see lava often, especially in deeper caves, which can kill the player very quickly and burn dropped items. Here are some tips to help with surviving in caves:
- Remember to always be aware of your surroundings in caves, especially upwards. One of the most common sources of mobs within previously explored caves is unnoticed openings in the ceiling or walls. If the player is in a ravine, watch out for monsters falling off of high ledges.
- A good mining practice is to fully explore and light a cave system before beginning to mine out any resources. It is extremely dangerous to stop and mine in a dark cave, where you can lose your loot if killed. Check for "broken bridges" such as gravel masses or 2-block drops. If monsters can come out of them, you may want to change that; once safety is verified, you can save the blocked-off areas for later.
- As part of exploration, "clean up" the area, taking off leftover blocks, filling small pits, and generally smoothing things out. In mineshafts, you can clear out most of the fence-and-plank "supports" as players "claim" an area. This will use a lot of axes, but it will improve both visibility and mobility, cutting down on unpleasant surprises. Notably, those fences provide better cover for creepers than they do for the player. This will also make it easier to tell where you are.
- Water coming down from above is especially troublesome, as it can carry monsters down from a whole chain of darkened caverns.
- It's a good idea to swim upwards and light the path of the flow.
- Most water flows can be captured at the source with a bucket; if that doesn't work out, they can be contained with fences or blocks. Either way, be aware of areas where the water flow formerly blocked monsters. Some flows may be useful to keep for travel — the player can swim up or down waterfalls to traverse high cliffs, or land in water to avoid fall damage. With a little care, you can swim along the outside of the waterfall, which lets the player keep breathing normally.
- Some water flows from cave ceilings come from openings in the seafloor. With care (and perhaps a door or some ladders), you can swim up these and mark the entrance with a jack-o-lantern, which will generally be visible from the sea surface. Such openings are also a quick way to get back to the surface if you've gotten lost. With a bit more effort, players can seal the opening altogether, perhaps leaving a shaft with ladders for their own use. (Ladders and signs can be used to block water.)
- Lava flows and pools can also block the passage. Like water, lava flows can be bucketed if you can reach the source, or contained with blocks otherwise. Lava pools can be flooded with water to convert them to obsidian. Again, be aware of areas where monsters were blocked by the lava. Also, remember to re-light the area after removing that brightly glowing lava.
- When fighting mobs, be careful of lava as mobs could knock you into it or you might walk into lava by accident and lose your items.
Here are some general miscellaneous tips that can help you when exploring caverns:
- To reach ores or tunnels high on the ceiling, try pillar jumping to gain altitude or use Ladders by placing new ones as the player climb. Players can also build bridges across ravines and pits.
- If the player sees a huge underground ravine and wants to see what's inside of it, and they want a way to get back up but don't want to take the time to mine or place blocks, pour water on the edge and it will flow down, allowing for a safe way to get down and up. Note that players must have a water bucket with them, or if they have an empty bucket with them, they will likely be able to find a water source to get water from.
When finished exploring a cave, it is best to try and find the way back to the surface via the way they have came, rather than by digging upwards. However, if need be, they can make their own exit — just dig upwards to the surface in a staircase fashion, watching for drips. Players can also dig directly upwards, however, be careful when doing so, as gravel could fall on you and cause suffocation. You should also keep an eye out for water droplets or lava droplets falling from the block above.
When digging a staircase out of a cave, it can be useful to check your map to figure out where you will, or want to, emerge. Coming out into the seabed can be tricky, especially if your torches get washed away. Put your torches 3 blocks up instead of 2 or 1 to avoid "wash-outs" (specifically: high enough that the air 1 block above the next higher stair isn't beside the torch).
Like mentioned previously, if you found a water flow that leads up to the ocean surface, you can use this to exit the cave. One can create easy access from the cave to the ocean surface by making a pillar of sugar cane. This will provide a fast, breathable path in both directions. This method can be used for both entering and exiting caves.