Grab your shovel and spelunking gear, the Grand Underground is a returning mechanic that has been massively expanded in Pokemon Brilliant Diamond and Shining Pearl.
As if the Sinnoh region didn't have enough to explore, the Grand Underground is packed with subterranean secrets to uncover.
Dedicated players might recognise the Grand Underground from the original games, but there's a lot of new things to root out along with the classic features. First up, there's the much-loved Secret Base mechanic, along with beautiful Pokemon Statues to display, tons of Hideaway Pokemon Encounters and easy ways to farm useful items.
There’s a long list of interesting things buried in the Underground as well as different Pokemon Hideaways to unearth, so we’ll go over everything you need to know about the Grand Underground in Pokemon Brilliant Diamond and Shining Pearl, as well as how you even get there in the first place.
- How do you unlock the Grand Underground in Pokemon Brilliant Diamond and Shining Pearl?
- What are the different areas in the Grand Underground?
- How do you dig in the Grand Underground?
- How do you make Secret Bases in the Grand Underground?
- Which Pokemon can I find in the Grand Underground?
- What items can I find in the Grand Underground?
- What are Pokemon Statues in the Grand Underground?
How do you unlock the Grand Underground in Pokemon Brilliant Diamond and Shining Pearl?
The Grand Underground is first accessible from Eterna City, home of Brilliant Diamond and Shining Pearl’s second Gym Leader, the grass-type user Gardenia.
In the house next to the Pokemon Center you can meet the Underground Man. He gives you the Explorer’s Kit, which unlocks access to the Grand Underground.
What are the different areas in the Grand Underground?
In the Brilliant Diamond and Shining Pearl remakes, the Grand Underground is again split up into 6 areas, but with different layouts from the original games.
The six areas are accessible from:
- Twinleaf Town
- Eterna City
- Celestic Town
- Snowpoint City
- Sunyshore City
- The Fight Area after the Elite Four
These 6 areas have different biomes, as well as different Pokemon Hideaways, and therefore different Pokemon encounters. Be sure to explore them all to reap the rewards throughout your adventure.
When you first go into the Underground, you'll see the normal tunnels. This is where you dig for items and plan your Secret Base.
The question marked rooms you see on the mini-map are Pokemon Hideaways where you can catch powerful additions to your team.
They're question marked to begin with, but once you enter them, you'll be able to see which kind of Hideaway it is every subsequent time.
As you explore, there are 17 kinds of Hideaway to stumble upon:
- Grassland Cave
- Spacious Cave
- Rocky Cave
- Fountainspring Cave
- Volcanic Cave
- Big Bluff Cavern
- Riverbank Cave
- Sunlit Cavern
- Swampy Cave
- Still-Water Cavern
- Typhlo Cavern
- Bogsunk Cavern
- Sandsear Cave
- Icy Cave
- Whiteout Cave
- Glacial Cavern
- Dazzling Cave
- Stargleam Cavern
The "Caves" are the small question mark rooms, while the larger ones at the end of paths are the "Caverns".
How do you dig in the Grand Underground?
Digging in the Grand Underground is as simple as interacting with the glinting, shiny points along the walls of the tunnels.
As part of your Explorer Kit, you have a blue claw hammer and a red mallet. Your goal is to excavate all of the treasure in the mini-game before the crevice at the top of the screen goes all the way from the right to the left.
The mallet uncovers more blocks, but causes a bigger cave-in. While the blue claw hammer chips away at the tunnel more slowly, but reveals fewer blocks.
You need to conservatively remove blocks on the wall with the blue hammer to find your items, then smash them out with the red mallet.
If you go overboard then the wall will collapse, leaving you with just the loot you’ve fully unearthed so far.
However, there are plenty of items to be found, so don’t worry too much about painstakingly chipping away every block - there’s always next time.
How do you make Secret Bases in the Grand Underground?
To make a Secret Base in the Grand Underground, you need to buy a Digger Drill from the wandering shopkeepers exploring the tunnels with you.
These cost between 10-20 Spheres - which you get from digging - depending on the shop.
You can then decorate your Secret Base with items and Pokemon Statues, which we’ll discuss more below.
Which Pokemon can I find in the Grand Underground?
Inside of the Pokemon Hideaways found in the Grand Underground, you can snag your version’s exclusive Pokemon, like Murkrow, Scyther, Elekid and Gligar in Brilliant Diamond, and Misdreavus, Magby, Pinsir and Teddiursa in Shining Pearl.
These areas also feature visible Pokemon wandering around like in more recent games in the series.
But that’s not all, as you progress through the game and earn more Gym Badges, you unlock more encounters alongside your ability to use HM moves outside of battle.
The Pokemon community has already done extensive research on what exactly these encounters are, like in the embedded video below by YouTuber HybridHero.
Once you've complete the main game by defeating the Elite Four, you unlock a huge amount more Pokemon through the Grand Underground.
This includes fan-favourite starter pokemon from the first 4 game generations. We're talking, Bulbasaur, Charmander and Squirtle, Totodile, Chikorita and Cyndaquil, Treecko, Mudkip and Torchic, as well as Turtwig, Piplup and Chimchar.
What items can I find in the Grand Underground?
It’s not just cool Pokemon you can find in the Grand Underground, but tons of rare and powerful items as well.
You can find:
- Spheres to trade with underground shopkeepers
- Shards to trade with the weather researcher on Route 212 for TMs
- Heart Scales to trade with Move Tutors
- Elemental Plates that boost the power of that kind of attack
- Mysterious Shards that you use to get Pokemon Slates in the post-game
- Fire, Water, Leaf, Thunder, Moon and Sun Stones
- The Oval Stone to evolve Happiny into Chansey
- Everstones to stop your Pokemon from evolving
- Weather prolonging items like the Damp, Smooth, and Heat Rocks
- Light Clay that prolongs Light Screen
- Pokemon Fossils
- Money items like Star Pieces
- Pokemon Statues, which we’ll talk more about later
This is pretty much the best way to farm the basic elemental evolution stones and Moon Stone in Diamond and Pearl.
We have a page on where to get the Dusk, Dawn, and Shiny Stones, here.
What are Pokemon Statues in the Grand Underground?
If you’ve ever loved Pokemon cards just as much as the game, you’ll know that collecting Pokemon merch can be just as exciting as earning your badges, and in Brilliant Diamond and Shining Pearl a little bit of that collect-a-thon bug has made its way into the video games.
When you participate in the digging mini-games in the Grand Underground, you have a chance to uncover special boxes. These contain Pokemon Statues you can display in your Secret Base to give you a bonus chance of encountering certain types of Pokemon in Pokemon Hideaways.
Pokemon Statue boxes are divided up by elemental types like Fire, Water, Grass, etc, and contain a representation of fan-favourite Pokemon.
You can get normal and Shiny variations of each statue, as well as statues of Legendary Pokemon.
You can get some Shiny Pokemon statues for free by entering Pokemon Brilliant Diamond and Shining Pearl Mystery Gift Codes - including the Sinnoh starters and 4th-gen Pokemon like Lucario and Electivire.
When you place a Pokemon Statue in your Secret Base you get a special bonus to the encounter rate of Pokemon with the same type as that Statue in your Grand Underground Pokemon Hideaways.
The more Pokemon Statues of the same type you have out on display, the bigger the bonus.
Apparently, according to testing done by PhillyBeatzU on YouTube, Shiny versions of Statues give a bigger bonus than the normal versions, while Statues of Legendary Pokemon give an even bigger bonus than Shiny.
To get more Shiny Statues, as discussed in the video above, you need to collect the Digglets and Dugtrios to fill the meter on the left-hand side of your screen, underneath the mini-map. Once this is full, you have an increased chance of unearthing Shiny Statues.
Deck out your base with multiples of the same type to get a better chance of snagging the encounter you’re after.
Before you go, remember to claim your free Manaphy Egg using Pokemon Brilliant Diamond and Shining Pearl's Mystery Gift feature!
For more on the Generation 4 remakes, you can check out our Pokemon Brilliant Diamond and Shining Pearl review impressions here!