Copperbell Mines is the third dungeon that your story quest takes you in a row and it is the first to actually require tactics in Final Fantasy XIV. Previous dungeons could easily be face rolled through or used a few surprise elements, but Copperbell Mines has two boss fights that can only be completed if you follow the specific instructions of each boss. Otherwise, the dungeon is rather short and should easily be completed in half an hour or so.
The dungeon requires you to be level 17 in order to enter.
Spriggans fill up most of the dungeon and are not linked to other packs; they can be safely pulled solo. Beyond that there are random gigas that will attack you seemingly without warning (twice in the dungeon). However, I didn't run into a problem with either encounter and don't expect you too. There isn't a lot of trash pulls in the dungeon.
As far as puzzles go, you'll need to blow up a few walls, however the Firesand and blasting caps are located nearby to the walls and shouldn't pose any kind of difficulty in obtaining.
This rather easy fight involves fighting increasing waves of spriggans until Kottos arrives. Kottos himself is no serious threat, but the spriggans can be. The tank needs to focus on making sure the healer is alive and I personally suggest a melee DPS take one or two spriggans and kite them around if possible to take some of the heat off of the tank.
This fight is very complex and will be the first fight that requires you to utilize the mechanics of the fight in order to get through it. Basically the Ichorous Ire is immune to damage. You have to place him on top of the stone and then use the blasting device to spawn a bomb. The bomb will eventually detonate, no one in the group needs to be inside of the circle, instead the Ichorous Ire needs to be inside of it (it moves slow enough that you can easily keep it in the targeting reticule).
At the same time, spriggans will be flooding into the room trying to kill the bomb (which stops the explosion) and basically be annoying. DPS needs to focus on the adds while the tank needs to focus on exploding the Ire. From my experience, most DPS classes can handle the limited damage from the spriggans. If not the tank can pick them up as well.
Anyway, it takes about three expansions, after each explosion the ire breaks into two (then four, then eight which can then be DPS'd down).
This fight is rather simple compared to the Ire you just fought. A huge gigas sits in the middle of the room, have the tank fight him. After some time he will bust open a hole in the wall, which is unavoidable, and every little bit a new gigas will enter the room and rush to the other side to attack the other wall. Should they succeed at breaking the wall down, wave after wave of spriggans will spawn. So the fight plays like this.
If the gigas is up, everyone focus on taking it down, otherwise focus on killing Gyges. The tank doesn't have to move Gyges really, outside of keeping him away from attacking his teammates.
Afterward if you're on your story quest, when you leave you'll be presented with a lengthy cutscene, otherwise you're done! This is the last story dungeon for a little bit, but is really good experience whenever you're attempting to level a subclass through 18 through 20.