In Pokémon Brilliant Diamond and Shining Pearl, the Grand Underground is certainly true to its name. The Grand Underground is large, packed with opportunities to dig for treasure, and the chance of fighting and catching Pokémon of different terrains while earning your party EXP.
In this guide, we explain how to enter the Grand Underground, take part in the digging mini-game, and build your secret base.
Read More: Pokémon Brilliant Diamond and Shining Pearl Stone Guide: How to Get Shiny Stone, Moon Stone & More
How To Enter the Grand Underground
To first be able to access the Grand Underground of Pokémon Brilliant Diamond and Shining Pearl, you will need to make your way to Eterna City. Just to the right of the Pokémon Center, there is a small house with an elderly man inside that you must speak to.
The man will gift you the Explorer Kit, which allows you to enter the Grand Underground from anywhere at any time. Depending on where you use the Explorer Kit, you will land in an area of the underground that aligns with where you were on the mainland. As you'll soon see, there is a hell of a lot of exploring for you to do!
Once in the Grand Underground, there's a lot to explore, shown on the map above. You can choose to enter Pokémon Hideaways and fight with Pokémon, or search for items such as evolution stones and fossils. On the other hand, you can run along the corridors in the hunt for treasure, which we talk more about below.
The Explorer Kit can be accessed from your bag at any time, and later registered to one of D-pad's buttons for easier access. To leave the Grand Underground, simply press 'Y' while there, and choose to 'Go Up'.
How To Play the Digging Mini-game and Get Statues
As you navigate the Grand Underground's corridors of Pokémon Brilliant Diamond and Shining Pearl, gold spots will be marked on your mini-map which indicate where treasure can be dug for and discovered. Alternatively, you can press R while running along the corridors to use your Dowsing Monitor (a part of your Pokétch) and any treasure will be shown by a glowing light on the walls.
Approach the wall and press 'A' to dig for treasure. Use the hammer to break away areas until you catch a glimpse of treasure. Then, use the pickaxe to carefully acquire the treasure without breaking the wall. Sooner or later, though, the wall will collapse, and you'll need to move onto the next digging spot.
By engaging in the digging mini-game, you'll be able to collect the following range of items:
- Evolution Stones
- Fossils
- Spheres
- Shards
- Boxes, containing Pokémon Statues
Pokémon Statues can be used to decorate your Secret Base, which can be shown off to other players when using online play.
How To Build and Use Your Secret Base
To be able to make a Secret Base in the Grand Underground of Pokémon Brilliant Diamond and Shining Pearl, you will need to continue speaking with the elderly man in Eterna City. He will assign you various tasks that teach you about the Grand Underground, and will eventually give you a Digger Drill.
Use the Digger Drill to build your Secret Base, but note that you can only have one base at a time and will need to acquire another Digger Drill (from a Sphere Trader) to move the base. Once built, you can place Pokémon statues in the base and use Pedestals you may have found to customise them. The statues that you place in your Secret Base will increase your chance of encountering these Pokémon in Pokémon Hideaways! You can also use Spheres you may have collected to expand your base and fit even more statues in it.
There you have it. That's all you need to know about the Grand Underground, the digging mini-game, and your Secret Base. For a little more guidance on making your way through Pokémon Brilliant Diamond and Shining Pearl, we recommend our beginners tips, our evolution guide, and our guide to countering each of the Sinnoh Region's eight gyms!