Costlemark Tower | Optional dungeons Final Fantasy XV Guide

Costlemark Tower is the hardest regular dungeon in the game, at least when it comes to the levels of the monsters lurking inside. The dungeon is quite peculiar, as you can access it only during the night - during the night the entrance will be locked. The recommended level to enter this dungeon is 55, although you shouldn't come here until you reach at least 70, as the enemies here are quite powerful. Remember to replenish your supply of curatives, especially Elixirs and Phoenix Downs.

• Location
• Enemies
• Walkthrough

Location

The entrance to Costlemark Tower.

Costlemark Tower is located in the southern part of the map, to the north of Galdin Quay city - the exact location of the entrance can be seen on the above screenshot. Remember that you can enter the dungeon only during the night - you can use the nearby fishing spot (to the north of the dungeon) to pass some time.

Enemies

The best weapons for this location are ones imbued with the power of Light, as all of the enemies (except for the boss) are vulnerable to them. When it comes to the boss, you can use Polearms or Machinery weapons, as well as Ice magic and you should avoid Fire. Ignis' Enchant ability is immensely useful here as well.

Walkthrough

The first group of enemies you will encounter here - Gelatin.

Once inside, follow the path until you reach a more spacious room - the first group of enemies, Gelatin, await you here. Those foes aren't exceptionally strong (aside from their resistances), which is why you shouldn't have any problems with them. Remember about their weakness to Light and exploit it to the fullest.

Galvanides are probably the most dangerous enemies in this dungeon.

Once the encounter is over, continue traveling along the path until you reach another rectangular room. Another battle will take place here, this time with Gelatins and Galvanides. The latter enemies are probably the most dangerous you'll face here - they deal high damage, are capable of inflicting damage to multiple characters at once. However, their most lethal ability is "self-destruct" - after several seconds of "swelling" Galvanides will start emitting electric discharges until finally exploding. The explosion deals immense damage and can sometimes kill the character on the spot (by causing Instant Death).

Ereshkigal are extremely annoying.

In the next room you will stumble upon a group of Ereshkigal. Those enemies are extremely irritating, jumping around the whole battlefield, performing sneak attacks or shooting projectiles from a large distance. Swords are the best group of weapons to use against them and patience is the key - you just have to wait for the parry prompt to appear on the screen and launch your counterattack. Mashing buttons won't help you at all, as the enemies can easily dodge those and attack from a different side.

The mentioned makeshift bridge.

Afterwards, approach the makeshift bridge made from a collapsed column and use it to get to the other side. Bussemand await you in the next room. Those foes are slow, but can deal high damage with their attacks. The best weapon to use against them is one from the Greatswords group - 3-4 strikes with it should be enough to bring them down. Take the enemies out, run down the stairs and jump from the ledge to reach a room with another group of Bussemands and Galvanides.

The stone passage mentioned in the paragraph.

Eliminate the enemies and jump to the lower floor. Another group of Ereshkigal will be here. Quickly take them out and note the collapsing floor - you will soon make use of it. Leave the room and go right to initiate another encounter. Afterwards, continue your march and enter the corridor going to the right for an encounter with yet another group of Ereshkigal. Once it's over, run into the rubble located south of your position and squeeze through a narrow stone passage.

A fire deposit.

A group of Black Flans and Galvanides await you on the other side. Take them all out and use the nearby fire deposit. You can now go up by using the platform and get to the other side of the corridor to finally reach the place where you've jumped off the ledge some time ago. Get back to the rubble, squeeze through the narrow passage again, turn left and continue along the corridor. You will end up in a familiar place - turn left and run straight ahead to get back to the room with the collapsed floor. Jump down to reach the lower floor.

You should be familiar with Yojimbo.

A new enemy should appear in the area - Yojimbo. You have to be careful when dealing with that foe, as his attacks can cause Instant Death, instantly killing a character he hits (or even the whole party if he is lucky enough). Defeat all the enemies in the area, go through the door and continue along the corridor, turning right at the end of it.

An encounter with Yojimbo and other monsters on a narrow bridge isn't a pleasurable one.

Go through the area and into another room, where you will stumble upon a group of enemies and a lightning deposit. Collect the resource, leave the room and move along the platform to reach yet another group of foes. Continue your march until you reach a long and narrow bridge. Here you will be fighting a group of enemies with a Yojimbo inside of it. Take them out and continue along the platform going down - you will encounter Bussemands along the way. You should soon reach a huge square room.

A red pressure plate visible in the distance.

The first thing to note here is the red pressure plate located on the ground - stepping on it will take you to the entrance of the dungeon. In the corners of the room you can find 4 small walls, with blue floor plates next to them. You can interact with those plates - doing so will move the plate down and lead you through a short corridor. Corridors are composed of sections - each time you want to move forward you have to interact with the glowing plate/wall (as with the plate at the beginning). This will move the walls, allowing you to continue walking through the corridor. After repeating the process multiple times you will get back to the huge square room.

You can move by interacting with glowing plates/walls.

Two things to remember about. First things first - you have to go through three such tunnels until you reach the fourth, correct one. You won't be able to bypass it, as only a single plate is active at a time. What is more, each time you get back to the large room you will be forced to fight a large group of monsters - consisting of Flanks and Red Giant(s). The enemies aren't that strong, but the Red Giant has huge health pool, making those encounters extremely tedious. Focus your attention on the Flans and then take out the giant.

You have to look for the interactive element of the floor, go through the tunnel (where you will be fighting enemies as well), get back to the large room, take out all of the enemies and repeat the process. The fourth corridor is the correct one and using it you will be able to get to the boss. Interactive plates are randomly selected, there's no "right order". However, it's not much of a problems - you just have to run around the square room and look for the correct one.

Note - there's a small hole in the wall located in this large room (you can find it in the western part of the area). On the other side of the hole there's an entrance to the most difficult dungeon in the game - Menace Beneath Costlemark Tower. More on that topic can be found in a separate chapter.

The fourth tunnel will lead you to this area.

Go through the three tunnels until you reach the fourth one. This one will lead you to a new room. There's an elevator located in the center of the room. Once you're ready, interact with the elevator to reach the boss of the dungeon, Jabberwock.

Ice spells are capable of dealing huge damage to the boss.

This encounter is one of the most difficult ones in the game. The enemy has a large pool of health points and even though it's not the fastest foe you've faced it can attack multiple characters at once. Additionally, one of its attacks inflicts Petrified effect, turning characters into stones, preventing them from moving for several seconds. Polearms, Machinery and Ice are the best tools against the enemy. Ice is probably the best choice against the dragon-like monster. You can create a Quintcast (or at least Quadcast) spell with the highest potency available. Thanks to that you will be able to deal (with a single spell!) from 39,996 to 49,995 points of damage, because all of the "hits" of the spell will deal 9,999 points of damage to the boss. As you can imagine, this will significantly reduce the boss' health pool.

You can leave the dungeon by stepping on the red pressure plate.

Once the encounter is over, you will be automatically rewarded with a new Royal Arm weapon - Sword of The Tall. Afterwards, use the nearby red pressure plate to get out of the dungeon. Congratulations, you've just cleared the last and most difficult of the "regular" dungeons in the game - more challenges can be found in "Menace Beneath Lucis" chapter.