Pokémon Pokopia: How to Unlock Mew – Mysterious Slates & Temple Guide

Why Unlocking Mew in Pokémon Pokopia Is So Weirdly Hidden

The moment it clicked for me was standing in Withered Wasteland, staring at a wall of 27 empty tiles and realizing all those random “Mysterious Slates (???)” I’d been hoarding for hours were actually the key to Mew. I’d almost sold the first couple because they didn’t seem to do anything.

After roughly a dozen hours of casual exploration and then another five of focused farming, I finally pieced together how the slates, the hidden temple, and the mural all connect. This guide walks you through every step I wish I’d understood from the start: how the slates actually spawn, how to efficiently farm all 27, where the secret chamber is, and exactly what you need to do in the temple to unlock Mew.

Big Picture: How Mew Unlocks in Pokémon Pokopia

Before diving into the details, here’s the high-level flow of the whole quest:

• There are 27 unique “Mysterious Slates” in the game.
• Each slate has a different Unown symbol hidden on the back.
• They’re found in random dig spots around Pokopia by breaking special rocks with Rock Smash.
• You cannot get duplicates until you’ve collected the full set of 27; every slate you find is new progress.
• All 27 are used on a mural wall inside a hidden chamber in Withered Wasteland.
• Once all 27 tiles are correctly placed, Mew appears for a special encounter.
• After befriending it, Mew follows you like a mythic companion and can move into a Habitat Dex home if you have space.

The game gives almost no clear hints about this chain, so it’s easy to ignore the slates or miss the temple entirely. That’s why I’ll start where the confusion usually begins: finding and managing the slates themselves.

Step 1 – Finding Mysterious Slates (Without Losing Your Mind)

My first slate came out of a glowing rock I broke purely for loot. It dropped an item with a bag icon and a name like “Mysterious Slate (???)”. I assumed it was vendor trash. Don’t make that mistake. These are the core of the Mew quest.

Where Slates Spawn

Mysterious Slates come from special dig spots all over Pokopia’s map. In practice, that means:

• Glowing rocks in the overworld.
• Cracked stone blocks that stand out from the environment.
• Occasional buried item markers detected by search abilities.

You need a Pokémon with Rock Smash assigned to your field abilities. When you’re standing in front of a glowing or cracked rock, press A to interact, then confirm Rock Smash. If a slate is inside, it pops out as a pickup just like any other item.

From my runs, the densest areas for slates were:

• Withered Wasteland – especially near rock formations and the paths around the Pokémon Center.
• Rocky or desert biomes with lots of breakable stones.
• Underground or cave-like side areas where the map naturally funnels you past clusters of rocks.

Tools That Make Slate Hunting Easier

The grind goes from tolerable to painful depending on how you set up your team. Here’s the setup that finally made it feel efficient:

• A Pokémon with Rock Smash (mandatory).
• A Pokémon with a Search-style field ability (anything that pings or highlights nearby hidden items).
• Access to the Itemfinder, if you’ve unlocked it, to catch buried objects you might otherwise miss.
• A movement or mount ability that lets you quickly sprint or ride between rock clusters.

With Search + Rock Smash, you’ll see how many potential dig spots you’ve been walking straight past. I spent hours early on just smashing obvious glowing rocks; adding Search almost doubled my slate finds per loop.

How Slate Uniqueness Works

This is the part that changed how I approached the grind: you cannot pull the same slate twice until you’ve found the whole set of 27. Every time a Mysterious Slate drops, it’s one you don’t already own.

That means:

• Every slate pickup is guaranteed progress toward Mew.
• You never have to farm “for a specific one” like in some older Pokémon games.
• Late in the grind, you may go longer between slate drops, but you’re not dealing with duplicates.

In the Bag, they appear under key items as “Mysterious Slate (???)” until you inspect them. You can select a slate and choose to “Inspect” or “Place” it on the ground to see the Unown symbol on its back, but you don’t actually need to do this until you’re in the temple.

Important: Don’t toss or sell them. Some players assume they’re flavor items because nothing obvious happens when you pick them up. I kept every slate and was glad I did once I discovered the mural.

Step 2 – Efficient Slate Farming Routes

Once I realized Mew was locked behind all 27 slates, I stopped being casual about it and built a loop. On my file, getting from 8–9 random slates to the full set took around 2–3 focused hours of rock smashing.

My Core Farming Loop

This is the loop that felt best for me:

• Start at Withered Wasteland Pokémon Center.
• Circle the immediate area, clearing every glowing and cracked rock you can see.
• Head outward along the main paths, using your Search ability to sweep the desert for hidden rocks and buried spots.
• Transition into nearby rocky biomes, hitting caves and cliffs where breakable stones cluster.
• Fast travel back to the Pokémon Center and repeat once you’ve cleared a wide radius.

Rocks and dig spots seem to respawn over time, so by the time you warp back and repeat, at least some will have reappeared. I found it more efficient to do a few broad loops than to obsessively camp a single spot.

Optional Drop-Rate Tricks

Some guides suggest that feeding certain greedy Pokémon (like local Snorlax variants) improves your chances of rare dig finds, including slates. In my experience, regularly offering items seemed to slightly increase how often I saw slates, but it’s not mandatory. Think of it as a small efficiency bonus, not a requirement.

If you’re short on time, focus on consistently smashing glowing/cracked rocks and using Search-those two things alone are enough to complete the set eventually.

Step 3 – Finding the Hidden Mew Temple in Withered Wasteland

I actually stumbled into the temple with only half my slates collected and walked away confused. The mural doesn’t explain itself, and nothing dramatic happens until you’ve placed all 27. Here’s how to find it deliberately once you’re ready.

Exact Path to the Secret Chamber

From the Withered Wasteland Pokémon Center:

• Walk to the right (and slightly north) from the Center.
• Head toward the back wall area near the Horsea Fountain-you’ll see a stone wall that doesn’t match the rest of the ruins.
• Stand in front of that wall and use Rock Smash on the suspicious section to break open an underpass.
• Go through the underpass. Inside, look to the left-hand side for more cracked rocks.
• Break those cracked rocks with Rock Smash to reveal a hidden passage leading deeper inside.

Follow that passage and you’ll emerge into a small underground chamber with a huge stone wall covered in 27 recessed tiles-this is the Mew mural.

If you’ve found the fountain but not the wall, or you’re hitting the wrong rocks, sweep the entire back edge of the map near the Center. The smashable wall blends in more than it should, and I missed it twice before finally noticing the slightly different texture.

Step 4 – Solving the Mural Puzzle with Your 27 Slates

This is the part where most people assume there’s some impossible trick. In reality, the puzzle is straightforward once you know how the slates behave inside the chamber.

Understanding the Unown Symbols

Walk up to the mural and press A. You’ll see 27 empty recesses in the wall. Each corresponds to one specific slate with a matching Unown symbol on the back.

To place a slate:

• Open your Bag while standing in front of the wall.
• Scroll to your Mysterious Slates.
• Select one and choose the option to “Use” or “Place in mural”.
• The game will show the slate’s Unown symbol and let you pick an empty tile on the wall.

When you put a slate on its correct tile, it will lock in place with a satisfying effect. If you try to put it on the wrong tile, it won’t accept it, so there’s no way to “ruin” the puzzle. It’s basically a giant matching game.

Efficient Placement Strategy

The puzzle allows brute forcing, but that’s painful with 27 slots. What finally worked for me:

• Start on the left side of the mural and go tile by tile.
• Pick a slate, look at its Unown symbol, and check which tile highlights as compatible.
• Place it, then immediately move on to the next slate in your Bag.
• Work in rows (left to right, top to bottom) so you don’t lose track of which tiles are unfilled.

Because the game prevents incorrect placement, the “strategy” is mostly about not wasting time swapping slates around. If you already inspected your slates earlier and wrote down which symbol is which, it’s slightly faster, but honestly not necessary.

Important: There are no partial rewards for a half-completed mural. You must place all 27 correct slates to trigger the event. I had around 18 in place when I first found the chamber and nothing special happened. The wall only woke up once I slotted in the final piece.

Step 5 – Triggering the Mew Encounter and Befriending It

Once the 27th slate clicks into place, the mural glows and reforms into a complete image. There’s a short cutscene: the symbols pulse, a strange energy fills the chamber, and a portal-like effect appears in front of the wall.

After the animation, Mew appears in the room.

Conditions Before You Finish the Puzzle

There are two practical things to prepare before placing your last slate:

• Make sure you have at least one free Habitat slot in your Habitat Dex. If all your habitats are full and no one wants to move out, the game may prompt you to free space before Mew can move in.
• Bring a reasonably leveled team just in case there’s a battle-style encounter or a test. On my run, the encounter leaned more toward a special befriending moment than a traditional fight, but the game does treat it as a mythic event.

Interact with Mew and follow the on-screen prompts. When it’s done, Mew is added to your Pokédex and becomes available as a follower Pokémon. One of its signature perks is a Teleport-style ability that makes moving around your island noticeably more convenient once you assign it.

From there, open your Habitat Dex, select a suitable habitat slot, and assign Mew as a resident to fully integrate it into your town.

Troubleshooting: Common Problems and How to Fix Them

“I Found the Mural but Nothing Is Happening”

If you’re in the chamber and the wall is silent:

• Open your Bag and count your Mysterious Slates. If you have fewer than 27, the event won’t trigger.
• Try placing what you have anyway; the wall will accept partial progress but won’t do the full cutscene yet.
• Go back to exploring—especially Withered Wasteland and rocky biomes—and resume slate farming.

“I’m Missing the Last Few Slates”

The final 3–5 slates always feel the worst. Remember:

• You cannot be stuck with duplicates before 27, so if a slate drops, it’s new.
• Revisit earlier regions you blasted through quickly; I found two late-game slates in early- and mid-game routes I’d stopped checking.
• Give rocks time to respawn—don’t just run the same tiny circle over and over.

When I hit 24/27, I forced myself to clear an entirely different biome instead of camping Withered Wasteland, and that’s when the last ones finally popped.

“My Bag Shows ‘???’ and I Don’t Know If It’s a Slate”

If an item has a bag-like stone icon and “Mysterious Slate (???)” in its description, that’s exactly what you want. The “???” is just the game hiding the Unown symbol until you inspect or use it. Don’t discard anything with that label.

“I Don’t Have Rock Smash Yet”

If you reached Withered Wasteland but can’t break the wall or rocks, you’re probably missing the Rock Smash field ability or a Pokémon that can use it in the overworld. Check your move tutors or story progression requirements; unlocking Rock Smash is non-optional for various side paths, so you’ll pick it up as you advance the main quests.

Is Chasing Mew Through the Mysterious Slates Worth It?

From a purely time/value perspective, the Mew quest in Pokémon Pokopia is a slow burn. You’ll spend hours breaking rocks, revisiting old routes, and staring at that mural before it does anything. It’s not a quick mythic giveaway.

But here’s my verdict after doing it the long way:

• If you enjoy exploration and completion, this quest is absolutely worth it. The slate system pushes you to comb through every biome and rewards you with one of the most iconic Pokémon as a permanent neighbor.
• If you’re mostly focused on battles or story only, the slate grind might feel like busywork until the final payoff. In that case, treat it as a background objective you chip away at while doing other tasks.
• As a quality-of-life reward, Mew’s follower presence and teleport ability make moving around Pokopia feel better once it’s on your roster.

For me, finally seeing that mural light up and watching Mew float out of the completed pattern felt like the right kind of “secret legendary” moment—quiet, earned, and tied directly to how well I’d learned the map. If you’re willing to commit to collecting all 27 Mysterious Slates, unlocking Mew is one of Pokopia’s best long-term goals.