Caverns or caves 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 your 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 food supply and weapon and armor durability, leaving you hungry and vulnerable to attacks, that can cause your death.
There are a number of ways to find caverns. Below is a table, designed to make cavern-hunting easier.
|Exploring Surface||By exploring the surface of the map, there is a good chance that an exposed cavern can be found.|
|Digging||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 half the time. 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 12 and have your exploration much more profitable rather than only having cut through ore veins that contain less. Quarrying on layer 12 can get you diamonds and lava pools, as well.|
|Listening||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.|
|Piston||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 20-30 blocks, along by at least 16 blocks (43 blocks for the Console Edition), 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.|
|Cartographer||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 you should bring with you into caverns.
- Weapons - Because of a cavern's low light level, mobs such as zombies, spiders, skeletons, 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 and arrows to fight off said mobs.
- Armor - As said before, lots of mobs spawn in caverns because of the low light level. Armor may be needed when exploring caverns, so as to give the player better protection against mobs. Armors can also be enchanted to have Fire Protection (for lava and burning), Projectile Protection (for skeleton's arrows), Feather Falling (for falling from a too high place), and 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.
- 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 make more. While jack o'lanterns aren't so easy to make in the field, they also can be used for marking directions in the cave. 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 high-saturated food such as cooked porkchop and cooked salmon. Cakes may bring up much hunger points, but will drain more easily.
- 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.
- 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).
- Wood - Bringing in a stack of wood will let you 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 you 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 you aid survival, and reach any exploration goals.
- (Water) buckets - Empty buckets stack (while water or lava buckets don't), but you'll want to keep at least one bucket already filled with water. This is is useful for turning lava into obsidian, allowing it to be safely walked on or mined (there can still be lava below it though. Keep the water flowing). This also useful for extinguishing yourself when on fire. Empty buckets can let you move water or lava springs out of your way, or collect more water (or lava) for your 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 you get completely lost, you can just simply dig up to the surface and use a compass to guide you home. Only helpful if your house is near the world spawn.
It is surprisingly easy to get lost in caverns. Below are a number of methods you 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 you go deeper in. This way, no matter how complicated and even intertwined the caves get, you can always find your way back because if the torch is on the left of a cave wall, that means you're heading towards the exit. Conversely, if it's on the right, it means you're heading deeper in.
Another tip is to use markings such as colored wool, or other blocks, to find where you came from. You can also put signs for further clarification, pointing to the direction in which you came from. Optionally, you can make an arrow shape with the blocks themselves.
While it will not help you in navigating the cave itself, it may be wise to bring a map with you into a large cave, should you get lost and need to dig your way out. Note that most caves occupy less area horizontally than they might seem, but interconnected caves and abandoned mineshafts can sprawl over huge distances. You might well map some new surface as you explore 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 you will see lava often, especially in deeper caves, which can kill the player very quickly. Here are some tips to help you survive in caves:
- Remember in caves to always look around 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 you're 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 you are 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 abandoned mineshafts, you can clear out most of the fence-and-plank "supports" as you "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 you!)
- 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—you can swim up or down waterfalls to traverse high cliffs. With a little care, you can swim along the outside of the waterfall, which lets you 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, you can seal the opening altogether, perhaps leaving a shaft with ladders for your own use. (Remember that ladders and signs block water.)
- Lava flows and pools can also block your passage as well as the monsters'. Like water, lava flows can be bucketed if you can reach the source, or contained with blocks otherwise. Lava pools can be flooded 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 in mob fights, be careful of lava as mobs could nudge you or you might walk into lava by accident and lose all 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 you climb. You can also build bridges across ravines and pits.
- If you see a huge underground ravine and want to see what's inside of it, and you 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 you must have a water bucket with you, or if you have an empty bucket with you, you will likely be able to find a water source to get water from.
When finished exploring a cave, you can make your own exit—just dig upwards to the surface in a staircase fashion, watching for drips. You can also dig directly upwards, however, be careful when doing so, as it can cause suffocation.
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.