This guide is undergoing heavy construction, and will be updated regularly with more specific details regarding the Cavern. Note that you cannot currently explore two of the four sections planned for the Cavern.

One of the primary activities available to you on any given day in Coral Island, Mining is crucial to your life as a farmer. It's one of only two ways to gather valuable Ores for upgrading your tools, and offers a wide variety of other materials that you can sell or use to craft items. Mining is not easy, however, and you'll have to delve long and deep into the earth to earn your rewards.

This guide will teach you the ins and outs of Mining in Coral Island. It's highly recommended to start Mining as soon as you can, given the advantages of upgrading your tools when it comes to constructing and maintaining a farm.

Unlocking Mining

Early on in your farming career (the fourth or fifth day, to be a little more exact) you'll receive a visit from Mark, a surly man who doesn't like to speak. Mark will inform you that the Cavern, a location through the forest to the northwest of your farm, has been opened for business. Travel there - a stone sign will point the way - and you'll meet Kira, another Cavern enthusiast. She'll warn you about monsters, and give you a Blunt Sword to fight them off.

From this point on you can enter the lower levels of the Cavern. When you first enter you can only explore the Earth Shaft of the Cavern, and will need to unlock the other three sections.

Mining Basics

Mining is pretty simple, and requires your Pickaxe at a minimum. Once you enter the first level of the Cavern you'll be faced with a room filled with rocks. You need to bash the rocks with your Pickaxe until you find a hole with a rope. You can use this rope to descend to the next level, where you'll find more rocks to bash, and another hole to discover. The deeper you get, the larger the spaces become - but the more valuable the items you can potentially find.

In addition to the copious amounts of Stone you'll receive from Mining you'll occasionally come across Ore. Locating and collecting Ore is your primary purpose for entering the Cavern, as you can use a Furnace to turn Ore into Bars. You can then submit one of your tools and your collection of Bars to the Blacksmith in Starlet Town. They will, in turn, upgrade your selected tool, making it more powerful.

Every five levels in the Cavern you'll find a floor with an elevator. You can use the elevator to return to the surface, or to jump to another elevator stop point that you've discovered. The contents of the Cavern are randomized each day, so if you fail to find an elevator before you run out of time and / or Energy you'll need to use the rope on your current level to leave, losing any progress you've made. As such it is crucial that you plan to descend at least five levels whenever you enter the Cavern.

Though the rule is that you'll find an elevator every five levels, there's an exception when your each level 30 of the Cavern. Do that and the next elevator will be ten levels down, not five. You'll need to pack for an extended, difficult trip to reach level 40, which is the bottom. Once you reach the bottom of the Earth Shaft you'll unlock the Water Shaft, and can start all over again.

Collecting Items

There are multiple ways to collect items while Mining:
  • The most obvious method is to bash rocks with your Pickaxe. You can receive a variety of different items this way, such as Coal, Coffers, or Geodes. Rocks with gems jutting out of them either contain Ore, or, more rarely, items that you can donate to the Museum.
  • You can also find Ore inside veins on the floor. Pay attention to the ground as you explore, and bash any colored cracks that you notice with your Pickaxe. This will start a minor chain reaction that you can exploit several times to receive a number of pieces of Ore.
  • The Cavern is littered with wooden boxes and barrels, usually sitting off to the side. Bashing these with your Sword, or simply dashing through them, will sometimes earn you items.
  • Monsters that you've killed will often drop items. More on this below.
  • When you reach specific levels of the Cavern you'll find treasure chests that contain set items. These will be noted below.


Exploring the Cavern is not a free ride, and as you get deeper you'll start running into monsters. These creatures can inflict damage to your Health, and if you run out of Health your trip into the Cavern will end for that day. It's generally a smart move to clear out any monsters populating a floor before you look for the exit, and since swinging your Sword doesn't cost any Energy there's nothing to lose besides time if you go for the monsters first.

The monsters you encounter while exploring the Cavern will change as you get deeper, and you'll run into more dangerous creatures at lower levels. We'll look at the monsters of the Cavern's various sections in another article.

Mining and Combat Mastery

As you explore the Mines you'll level two proficiencies, namely Mining and Combat. Your Mining Skills will improve your ability to destroy rocks, while Combat will make you better at killing monsters. It is highly recommended that you use up your Skill Points immediately after you get them in both categories, as the Skills you can learn make exploring the Cavern much easier.

Treasure Chests

Every ten levels that you descend into the Cavern you'll find a treasure chest. This chest contains a fixed reward for reaching that level. The rewards are as follows:
  • Earth Shaft level 10: 20 Slime Goops
  • Earth Shaft level 20: 10 Explosive Is
  • Earth Shaft level 30: 2 Jamus
  • Earth Shaft level 40: 4 Jamus
  • Water Shaft level 10: 10 Explosive IIs
  • Water Shaft level 20: 10 Explosive IIIs
  • Water Shaft level 30: 3 Jamus
  • Water Shaft level 40: 6 Jamus
(I'll continue to update this list as I explore the Water Shaft.)

Further Tips

Now that we've covered the fundamentals of exploring the Cavern, it can't hurt to delve into some tips and tricks for making the most of your Mining.
  • Complete the quests Mythical Dream and Temple Offering before you spend too much time in the Cavern. Doing this will unlock Fast Travel, and there's a Fast Travel point right outside the Cavern. You'll save travel time each day by unlocking this Fast Travel point.
  • Make sure you empty your inventory of everything you don't need before you enter the Cavern. You'll pick up many items, and having to decide whether or not you'll take something home with you can be a rough call.
  • Upgrade your Pickaxe as early as possible. The Bronze Pickaxe on its own will cut your time chopping through rocks almost in half, saving you a substantial amount of Energy. If you make a regular habit of entering the Cavern then no other tool in the game will get as much use as the Pickaxe.
  • Plan to descend five levels at a time, and no more. If you try for more than five levels in a single Cavern run you'll likely run out of Energy and / or time before hitting an elevator stop.
  • Keep a close eye on your Energy at all times. If you're running low you should prioritize finding an exit, rather than looking for extra stuff.
  • Stop smashing rocks as soon as you find an exit point. Have one more look around to make sure you didn't miss anything valuable, then go down. Don't bother smashing any more normal rocks on your current level. There will be plenty more on the next level.
  • Craft Explosives whenever you can. You'll learn how at Mining level 1, and they're fairly inexpensive at one Bronze Ore and four pieces of Coal. You'll find plenty of both as you explore the Cavern. These sticks of dynamite will allow you to destroy large numbers of rocks in a single explosion, and can save your butt if your Energy is running low with no exit hole in sight.
  • Every Mining and Combat Skill is useful in the Cavern, but you'll get the most use out of Rock Domino I and II. Rock Domino occasionally triggers a chain reaction when you break a rock, resulting in the destruction of other nearby rocks. This can save you a lot of Energy if you're out of Explosives. Note that Rock Domino only goes off if you can destroy a rock in one hit, so you'll need to keep your Pickaxe upgraded for the Skill to be useful.