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Final Fantasy 15 locked doors - How to open them and explore their high level mazes for the Menace Beneath Lucis quests

How to unlock and beat some of the game's toughest challenges.

Locked doors will block your path at the end of many dungeons and tombs in Final Fantasy 15, but fear not, there is a way to open them - eventually.

These doors extend lower level dungeons into very high level mazes that stretch underneath, and unlock once you've completed several other tough dungeons later in the game.

How to open the locked doors in Final Fantasy 15

You may have come across mysterious locked doors in the dungeons, but there are three requirements to getting through them. First, you need to have completed the main story. Second, in addition to the dungeons you tackle during the plot you'll also need to have defeated the bosses in Crestholm Channels, Balouve Mine, Costlemark Tower, and Daurell Caverns.

Cover image for YouTube videoLet's Play Final Fantasy 15 - WHAT IS GOING ON (Xbox One Gameplay)
Let's Play Final Fantasy 15 - WHAT IS GOING ON (Xbox One Gameplay)

If you've met those two criteria then you can now fulfil the third; head to Meldacia Hunter HQ just east of the Vesperpools and talk to Ezra, the old woman sat outside. She'll give you a key that will unlock the eight doors, and a series of sidequests will be added to your log.

Where are the locked doors in Final Fantasy 15 and how to prepare for A Menace Beneath Lucis

All the dungeons are structured in the same way: a series of caverns are linked by stone passages that descend ever lower, each room contains a group of monsters that must be defeated to progress to the next, and about half way down you'll find a campsite.

The final room will contain the dungeon boss, usually a scaled up version of one of the enemies that have been in the chambers leading to the end.

A list of the eight locked door dungeons with their recommended levels are as follows:

  • Keycatrich Trench (recommended level 55)
  • Fociaugh Hollow (recommended level 65)
  • Glacial Grotto (recommended level 65)
  • Daurell Caverns (recommended level 72)
  • Balouve Mines (recommended level 78)
  • Steyliffe Grove (recommended level 86)
  • Crestholm Channels (recommended level 92)
  • Costlemark Tower (recommended level 99)

If you're playing on Easy, note that the 'Ruby Ring' resurrection does not work in these dungeons - when you die, you die. Bring as many Hi-Potion, Hi-Elixir, Megapotion, and Megalixirs as you can, and stockpile magic to bring with you - there's no way of topping up either once you're in the dungeon.

Note that it's also possible to leave yourself in a position where your team aren't available for a fight - as soon as combat begins a door seals off the entrance, but the other members of the gang seem to like to dawdle so you need to wait just outside the entrance to make sure they're there, wait for the monsters to move as far away as possible, creep into the room, and make sure everyone is present and correct before staring the fight.

A Menace Beneath Lucis - how to complete each high level maze

Keycatrich Trench locked door (55 recommended)

  • Number of campsites: 1
  • Ereshkigal; vulnerable to Swords, Shields, Fire, and Royal weapons, resistant to Lightning.
  • Galvanade; vulnerable to Guns, Mechanisms, and Royal weapons, absorb Lightning.
  • Black Flan; resistant to everything apart from Royal weapons.
  • Marshmallow; vulnerable to Fire, Lightning, and Royal weapons, resistant to everything else.
  • Hecteye; vulnerable to Javelins, Shields, and Royal weapons, no resistances.
  • Final boss: Lakhmu Flan; scaled up version of Black Flan. Level 61, 274,000 HP.

Fociaugh Hollow locked door (65 recommended)

  • Number of campsites: 1
  • Yojimbo; weak to Javelins, Guns, Lightning, and Royal weapons, resistant to Fire.
  • Ganymede: vulnerable to Broadswords, Shields, and Royal weapons, resistant to Fire.
  • Ziggurat: vulnerable to Javelins, Shields, Lightning and Royal weapons, resistant to Fire.
  • Skeleton; vulnerable to Broadswords, Mechanisms, Ice, and Royal weapons, resistant to Lightning.
  • Aramusha; weak to Javelins, Guns, Lightning, and Royal weapons, resistant to Fire.
  • Final boss: Chandravarma; vulnerable to Royal weapons, resistant to everything else. Level 73, 285,600 HP.

Glacial Grotto locked door (65 recommended)

  • Number of campsites: 2
  • Cryonade; vulnerable to Guns, Mechanisms, Fire, and Royal weapons, absorb Ice.
  • Skeleton; vulnerable to Broadswords, Mechanisms, Ice, and Royal weapons, resistant to Lightning.
  • Elder Coerl; vulnerable to Swords, Daggers, Fire, resistant to Lightning and Royal weapons. These guys can one-shot you with an electrical attack, so avoid giving them time to charge if possible, or back off when their whips start to emit a large bright light.
  • Final boss: Kengo; scaled up version of a Ronin, vulnerable to Javelins, Guns, Lightning, and Royal weapons, resistant to Fire. Level 71, 290,200 HP.

Daurell Caverns locked door (72 recommended)

Getting in to here is a challenge in itself. As you approach the locked door you'll be attacked by an Iron Giant and some Hecteyes; when the fight is nearly over use the Warp Point near the marker to reach the upper platform and let the rest of the team finish it off, then climb down the ladder to give them a route up.

  • Number of campsites: 2
  • Voretooth; vulnerable to Javelins, Shields, and Ice, resistant to Fire and Royal weapons. Can deal poison damage.
  • Coerl; vulnerable to Swords, Daggers, Fire, resistant to Lightning and Royal weapons. These guys can one-shot you with an electrical attack, so avoid giving them time to charge if possible, or back off when their whips start to emit a large bright light.
  • Shieldshears; vulnerable to Javelins, Guns, and Ice, resistant to Fire and Royal weapons.
  • Sir Tonberry; vulnerable to Swords, Broadswords, and Ice, resistant to Lightning.
  • Malbodoom: vulnerable to Broadswords, Mechanisms, and Fire, resistant to Ice.
  • Custard; immune to everything other than Fire, Ice, and the Ring of Lucii. You can use magic on these guys, but there are a lot of them so it's likely you'll run out. Ignis has a Firestorm ability which you should use as often as you can, but the bulk of the damage you'll be dealing will probably be with the Ring - keep locked on to one of the enemies, and every time it attacks hit Square/X to deal some dodge damage.
  • Dolce; immune to everything other than Ice and the Ring of Lucii, absorb Fire. Do not use Ignis' fire attacks or fire magic on them as they absorb it and will heal - Ice magic and grinding away with the Ring are your only options.
  • Iseultalon; vulnerable to Shields, Mechanisms, Fire, and Royal weapons, resistant to Ice. Level 72, 230,200 HP sub-boss.
  • Final boss: Mahanaga; vulnerable to Swords, Shield, Lightning, and Royal weapons, resistant to Fire. Can cause Petrification and Toad. Level 78, 380,800 HP.

Balouve Mines locked door (78 recommended)

  • Number of campsites: 1
  • Voretooth; weak to Javelins, Shields, and Mechanisms, resistant to Fire. Can inflict Poison.
  • Killer Wasp; weak to Javelins, Daggers, and Ice, resistant to Lightning.
  • Mindflayer; weak to Javelins, Daggers, and Lightning, resistant to Ice. Can induce Confusion.
  • Hobgoblin; weak to Broadswords, Mechanisms, and Fire, resistant to Lightning.
  • Final boss: Psychomancer; weak to Broadsword, Shield, and Ice, resistant to Lightning. Can induce Confusion and Petrification, and potentially capable of one-shotting you with a grab attack. Level 82, 445,500 HP.

Steyliffe Grove locked door (86 recommended)

This dungeon is a test of endurance and resource management, and it will take a while to work through - we spent a little under six hours plugging away at it, so make sure you've not got any pressing engagements before you start!

There are around 100 rooms to fight through so pace your use of healing items as much as possible - focus on keeping yourself alive, make use of Ignis' Regroup ability instead of Potions when possible, and only restore the full HP of your other party members when they start becoming a liability. You can earn around 750,000 EXP on the run so there's an element of risk and reward - you can either use the campsites to save your progress, or risk running the whole thing without saving and then staying at a hotel when you're done to get a massive windfall.

  • Number of campsites: 9
  • Custard; immune to everything other than Fire, Ice, and the Ring of Lucii. You can use magic on these guys, but there are a lot of them so it's likely you'll run out. Ignis has a Firestorm ability which you should use as often as you can, but the bulk of the damage you'll be dealing will probably be with the Ring - keep locked on to one of the enemies, and every time it attacks hit Square/X to deal some dodge damage.
  • Dolce; immune to everything other than Ice and the Ring of Lucii, absorb Fire. Do not use Ignis' fire attacks or fire magic on them as they absorb it and will heal - Ice magic and grinding away with the Ring are your only options.
  • Matcha Mousse; vulnerable to Fire, resistant to everything else, and absorb Ice and Lightning.
  • Killer Wasp; weak to Javelins, Daggers, and Ice, resistant to Lightning.
  • Mindflayer; weak to Javelins, Daggers, and Lightning, resistant to Ice. Can induce Confusion.
  • Psychomancer; weak to Broadsword, Shield, and Ice, resistant to Lightning. Can induce Confusion and Petrification, may spawn a few skeleton henchmen, and potentially capable of one-shotting you with a grab attack.
  • Imp; vulnerable to Daggers, Guns, and Ice, resistant to Fire.
  • Ronin; vulnerable to Swords, Dagger, and Lightning, resistant to Fire.
  • Tonberry; vulnerable to Daggers, Guns, and Ice, resistant to Lightning. These guys are deceptively troublesome, have in excess of 300,000 HP, and take a long time to wear down, so when fighting more than one it's advisable to focus on them one at a time; use Libra to scan one so you can keep track which your target is.
  • Master Tonberry; vulnerable to Swords, Broadswords, and Ice, resistant to Lightning. Even more of a pain to wear down than the vanilla variety as they have over half a million HP, but you'll only ever face one at a time.
  • Kingatrice; vulnerable to Broadswords, Mechanisms, and Fire, resistant to Ice.
  • Griffon; vulnerable to Javelins, Daggers, and Fire, resistant to Ice.
  • Final boss: Mictlantecihuatl; vulnerable to Javelins, Daggers, and Ice, resistant to Lightning. It has a wide AoE lightning attack that can deal a lot of damage to the party, so when he charges head for the edge of the room. There's a small wall in one of the corners you can use as cover to heal and regain MP, but it doesn't actually provide cover in a practical sense so use with caution. Level 90, 457,900 HP.

Need more help? Our Final Fantasy 15 guide and walkthrough can provide tips on main story, as well as the open-world's many quests and activities. Learning how to get AP fast, EXP fast and money or Gil fast will aid you in many optional dungeons and tombs - including how to open and explore their locked doors. There's also plenty of interesting side-quests, too, such as the Scraps of Mystery and Professors Protege frog locations. And if you want to get around easier, you can rent a Chocobo, learn the infinite sprint trick and later in the game, get the flying car Regalia Type F. There's also more to see and do with DLC, such as Episode Gladiolus and Episode Prompto.


Crestholm Channels locked door (92 recommended)

  • Number of campsites: 2
  • Coraldevil and Seadevil; weak to Swords, Guns, and Ice, resistant to Fire.
  • Hvirtormr; weak to Swords, Daggers, and Ice, resistant to Fire. If you manage to block its head-strike move you'll go for a quick ride on its snout - hit Circle/B when prompted to deal additional damage.
  • Killer Wasp; weak to Javelins, Daggers, and Ice, resistant to Lightning.
  • Gaiatoad; weak to Javelins, Mechanisms, and Ice, resistant to Lightning.
  • Phalaris; weak to Broadswords, Shields, and Fire, resistant to Ice. Can induce Petrification, and watch out for its roll attacks.
  • Malbodoom; weak to Broadswords, Mechanisms, and Fire, resistant to Ice.
  • Final boos: Manxom. Can't be analysed, but by a process of elimination it seemed to be weak to Javelins and resistant to Broadswords, Daggers, and Fire. Level 95, unknown HP.

Costlemark Tower locked door (99 recommended)

This dungeon adds a twist - once through the locked door you can't use any items, so before you even consider entering there are a few things to do in preparation that will make life much easier.

First, you should get Ignis' cooking skill up to level 9 to acquire the Lasagna al Forno recipe and then stock up on ingredients to make plenty of them; the wheat can be purchased from Old Gobunant's Boat and the remaining ingredients are available at Gamberetto's Catch, both located in Altissia. This recipe provides a 4,000 HP boost and immunity to all elemental attacks, both of which are invaluable.

Second, equip the Megaphone on Gladio and the Black Choker on Noctis - the Megaphone can be picked up from Myrlwood Dungeon, and the Black Chocker is in Costlemark. Between them they give you around 600 HP recovery a second, increasing survivability by a large margin.

As with previous forays, make sure you're carrying as many high-powered spells as you can, and if you have available slots equip the best HP-boosting items you have and unlock as many HP boosting Ascension abilities as you can - a combination of those and the food should push all your party up to the maximum 9999 HP.

When you fight, remember that you staying alive is much more important than everyone else surviving, and for some encounters your may want to hang back a little - enemies with grab attacks (Giants, Mindflayers, Malboros, etc.) won't use them on the rest of the team, so Warping in for a couple of hits and then Warping out of harm's way and letting everyone else get on with it reduces the chances of being marmalised.

  • Mindflayer/Braindrainer; weak to Javelins, Daggers, and Lightning, resistant to Ice. Can induce Confusion.
  • Hobgoblin; weak to Broadswords, Mechanisms, and Fire, resistant to Lightning.
  • Havocfang; vulnerable to Broadswords, Daggers, and Ice, resistant to Fire.
  • Goblin; weak to Javelins, Daggers, and Fire, resistant to Ice.
  • Malboro; weak to Broadswords, Mechanisms, and Fire, resistant to Ice.
  • Jormungand; weak to Swords, Daggers, and Ice, immune to Fire. Has a devastating Fire AoE attack, but if you've had your Lasagna you'll be completely unharmed by it.
  • Iron Giant; weak to Broadswords and Shields, resistant to Lightning, and absorbs Fire. You'll fight two at once, shortly followed by four at once.
  • Elder Coerl; vulnerable to Swords, Daggers, Fire, resistant to Lightning and Royal weapons. These guys can one-shot you with an electrical attack, but Lasagna renders it completely ineffective.
  • Uttu; weak to guns, broadswords, and Fire, resistant to Lightning.
  • Final boss: Bilröst; basically a damage-sponge version of Jormungand, weak to Swords, Daggers, and Ice, immune to Fire. Level 99, 649,700 HP.

Finishing It All Off

Once all eight locked dungeons are clear head back to Ezra and she'll give you a Hunter's Medal - it's a one-off item that can be combined with spells to make a much more powerful version, but at this point there's probably not much left for you to kill so the main reward is satisfaction at a job well done.