The Fields of Mistria Mines begin as an early progression unlock, but in version 1.0 they are also the backbone of one of the game's longest story chains. Opening the entrance is only the beginning. From there you descend through multiple biomes, break magical seals, unlock new spells and materials, reach the Ancient Ruins on Floors 81–99, solve the Floor 90 Magic Key puzzle, and eventually arrive at the Final Seal on Floor 100.
If you only want the first entrance, complete the Unlocking the Mines story progression and trigger the entrance cutscene. If you are already inside and wondering how the current 1.0 Mines actually end, continue with the Floor 90 Puzzle Guide, Caldarus Guide, and Seridia Guide.
The short answer: how to unlock the Mines
You do not open the Mines by mining through the entrance manually. The game uses the Unlocking the Mines story quest and its entrance event. Continue the town story until that quest becomes active, travel to the Mines entrance, and let the associated cutscene finish. After that, the Mines become part of your regular progression route.
If the entrance is still closed, focus on the active story and Town progression rather than collecting a random item list from an old guide. Your quest log, letters, and current restoration objectives are the reliable signals for the initial unlock.
Step-by-step first unlock
- Continue the town restoration story. Complete the objectives currently available in your save.
- Check your quest log for Unlocking the Mines. This is the initial entrance quest, not one of the later seal quests.
- Travel to the Mines entrance once the quest is active.
- Let the entrance cutscene complete.
- Enter the Mines and begin exploring. Ore, gems, monsters, artifacts, story tablets, and deeper biome gates all become part of the progression loop from this point onward.
If you are also raising Town Rank, use the Town Rank and Renown Guide in parallel. Mining, Museum donations, quests, and Town Repair eventually overlap heavily in the late game.
Opening the Mines is not the end of the unlock chain
One of the biggest sources of confusion comes from Early Access guides. Older pages often describe the available Mines depth at the time they were written, then stop. Version 1.0 now contains the complete Mines storyline, so seeing another sealed passage deeper underground does not mean your original entrance unlock failed.
Think of Mines progression as a chain:
| Stage | What it means |
|---|---|
| Unlocking the Mines | Opens the initial Mines entrance |
| Earlier seal quests | Progress through the elemental biomes and restore Dragon Magic |
| Breaking the Fire Seal | Major Caldarus milestone and access toward the Deep Woods |
| Breaking the Ruins Seal | Unlocks the Ancient Ruins, the final Mines biome |
| Floor 90: Find the Magic Key | Opens the route through Floors 91–100 |
| Breaking the Final Seal | Completes the core Mines storyline and unlocks major late-game character progression |
This structure is important for both story and SEO intent: “unlock Mines” is the entry point, while Floor 90 and the Final Seal are later progression problems rather than separate unrelated systems.
The Ancient Ruins: final Mines biome
The Ancient Ruins are the fifth and final Mines biome and occupy the late stretch of Floors 81–99. Access is tied to Breaking the Ruins Seal. Unlike early floors, this area is deliberately darker and contains late-game materials such as Mistril along with new monsters and story rooms.
Mistril equipment helps with visibility in the Ruins because equipped pieces increase the light radius around the player. The biome also contains the fixed Floor 90 story area and leads to the Final Seal on Floor 100.
If you are here for Museum cleanup rather than only story progression, the Museum Guide and Terrarium Guide are useful companions. Terrarium-produced bait and pheromones can be used in the Mines after the relevant patch changes, helping with rarity-specific collection goals.
Floor 90: Find the Magic Key
Floor 90 is a fixed story puzzle inside the Ancient Ruins. The quest Find the Magic Key requires more than ordinary mining.
The condensed solution is:
- Activate the Dragon Forge using Dragon's Breath.
- Explore the Priestess rooms and interact with the relevant tablet.
- Offer 1 Marigold and 1 Temple Flower.
- Receive the Seed of Balance.
- Plant it in the dedicated Floor 90 field.
- Water it until mature, or accelerate it with Growth Spell.
- Harvest the Magic Key.
- Use the key to open the route toward Floors 91–100.
For exact rooms, troubleshooting, and the embedded video walkthrough, use the dedicated Floor 90 Puzzle Guide.
What happens after Floor 90?
Once the Magic Key route is open, continue descending through the Ancient Ruins. Late progression uses the Dragon Forge for special Dragon-Forged materials. Four of those materials are required at the Final Seal:
- Dragon-Forged Fang
- Dragon-Forged Horn
- Dragon-Forged Core
- Dragon-Forged Powder
These are not simply optional endgame crafts. They are the required offerings for Breaking the Final Seal on Floor 100.
Completing that quest finishes a major portion of the Mines story, opens the northern portion of the Western Ruins, and unlocks Seridia relationship progression. It also matters directly to Caldarus: even at 10 Hearts, you cannot complete his marriage proposal route until Breaking the Final Seal is finished.
That creates one of the strongest late-game internal-link paths on the site:
Mines → Floor 90 → Final Seal → Seridia / Caldarus → Romance / Marriage
Caldarus and the Mines
Caldarus is tied to the Mines much earlier than Seridia. His early relationship progression follows the tablet and seal storyline, and Breaking the Fire Seal is the major milestone that leads toward his human form and Deep Woods route.
His story still does not fully separate from the Mines after that point. Current 1.0 progression keeps his marriage route blocked until Breaking the Final Seal is complete. So if you reach 10 Hearts with Caldarus but the Engagement Ring cannot lead to a proposal, the issue may be story progression rather than friendship.
Seridia and the Final Seal
Seridia is even more directly tied to the end of the Mines. The mysterious Priestess guides the player through the late Ruins progression, including the Floor 90 area. After the four Dragon-Forged materials are offered at Floor 100 and the Final Seal breaks, her identity is revealed and her relationship progression unlocks.
This is why Seridia should not be treated like an ordinary early-town romance candidate. Her character page belongs naturally at the end of the Mines content cluster as well as inside the Romance cluster.
Mines and Town Repair overlap in the late game
Town progression and Mines progression eventually converge. The late Repair the Bell Tower project requires Dragon-Forged Fang and Dragon-Forged Core, so a player who grinds Town Rank without progressing the Mines can hit a material wall.
Use the Town Repair Questline Guide and Town Rank Guide alongside Mines progression. A practical late-game plan is to push both tracks together: gain Renown through quests and Museum work while gathering Mistril, monster drops, and Dragon Forge materials underground.
After the Saturday Market expansion, Stillwell's Mission Board also gives you a reason to revisit Mines biomes for monster-slaying missions worth substantial Renown.
If the entrance or deeper progression is stuck
The Mines entrance is closed
Confirm that Unlocking the Mines is active and that you have completed the entrance cutscene. Continue available story objectives if the quest has not appeared yet.
I can enter but cannot reach the Ancient Ruins
Continue the seal questline. The Ancient Ruins are unlocked through Breaking the Ruins Seal, not through the original entrance quest.
I am stuck on Floor 90
You need the Magic Key puzzle rather than a normal ladder. Use Dragon's Breath on the Dragon Forge, offer Marigold and Temple Flower, grow the Seed of Balance, and harvest the Magic Key.
I reached Floor 100 but cannot break the Final Seal
Craft the four required Dragon-Forged materials—Fang, Horn, Core, and Powder—at the Dragon Forge and offer them at the Final Seal.
Caldarus will not accept my proposal
Complete Breaking the Final Seal. Current 1.0 documentation explicitly blocks his marriage proposal before that story quest is finished.
Seridia is still not a normal relationship character
Finish Breaking the Final Seal. That quest explicitly unlocks Seridia relationship progression.
Mines progression checklist
- Trigger Unlocking the Mines and open the entrance.
- Progress through the earlier elemental Mines biomes and seals.
- Complete Breaking the Fire Seal for major Caldarus progression.
- Complete Breaking the Ruins Seal to enter the Ancient Ruins.
- Reach Floor 90 and finish Find the Magic Key.
- Continue through Floors 91–100.
- Craft Dragon-Forged Fang, Horn, Core, and Powder.
- Complete Breaking the Final Seal.
- Continue Seridia and Caldarus late-game relationship content.
- Use Dragon-Forged materials for late Town Repair when required.
- Revisit Mines biomes for Stillwell missions, Museum items, and endgame materials.
Related guides
- Floor 90 Puzzle Guide
- Caldarus Guide
- Seridia Guide
- Town Repair Questline
- Town Rank & Renown
- Stillwell Mission Board
- Museum Completion Guide
- Fields of Mistria 1.0 Guide
