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Pokémon: Brilliant Diamond & Shining Pearl

How to Make a Secret Base in the Grand Underground

Seren Morgan-Roberts

This page offers a guide on how to unlock and build a Secret Base in the Grand Underground in Pokémon: Brilliant Diamond & Shining Pearl.

Grand Underground Secret Base.

How to Get Digger Drill

To build a secret base, you’ll need the Digger Drill. You can get this for free from the Underground Man found in the house to the right of the Pokémon Center in Eterna City. He is the same man who will have given you the Explorer’s Kit. You’ll have to complete two tasks for him, though they can both be done in the same visit to the Grand Underground so don’t feel like you need to return in between. The first task is to just venture into the Grand Underground, and then the second task is to do some digging! You can do both in one trip and return to get the rewards for both tasks at once - you get the Digger Drill for doing your first dig. If you’re unsure on how to dig, head over to our quick tutorial for some tips!

You can also buy Digger Drills from Sphere Traders in the Grand Underground.

(1 of 2) Head over to Eterna City and go into the house to the right of the Pokémon Center

Head over to Eterna City and go into the house to the right of the Pokémon Center (left), if you’ve completed his tasks, he’ll give you a Digger Drill! (right)

How to Build Secret Base

Once you have the Digger Drill, creating a Secret Base is super easy! Head down into the Grand Underground using your Explorer’s kit and pick any wall where you’d like a Secret Base. Press A when facing your chosen wall and you’ll get the option to create an opening into a Secret Base. You can only make one, and if you choose to use your Digger Drill again, then you’ll destroy your previous base and it’ll also break your Digger Drill - meaning you’ll have to buy another from a Sphere Trader in the Underground.

(1 of 2) First pick a spot

First pick a spot (left), then build your cave - easy! (right)

What Can you Do in Your Secret Base?

The Secret Base is used to display the Statues you find during your diggings in the Grand Underground. You can find shiny ones too! For more information on all the statues, head to our Statues List.

To decorate, interact with the orb to the right of the cave entrance and then choose to place down statues (if you have some, of course). Placing down Statues will increase the encounter rate of the displayed Pokémon’s type in the various caverns.

(1 of 2) Choose your statues

Choose your statues (left), and place as many as you like (or can!) in your base! (right)

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Guide Information
  • Publisher
    Pokemon Company International
  • Platforms,
  • Genre
  • Guide Release
    29 October 2021
  • Last Updated
    23 April 2022
    Version History
  • Guide Author

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This strategy guide for Pokémon Brilliant Diamond & Shining Pearl contains all the information Pokémon trainers will need to complete the game and catch every single Pokémon!

In this remake of the classic Pokémon Diamond & Pearl, you’ll journey through the mystical Sinnoh region to become a Pokémon master. Along the way, you’ll confront the scheming Team Galactic and witness the awesome power of the Legendary Dialga or Palkia.

Currently included in our guide:

The following will be available via free updates to our guide:

  • A complete walkthrough of the main story and postgame.
  • A full guide for Super Contest Shows.
    • How to cook the best quality Poffins.
  • Explanation of advanced mechanics, such as IVs and EVs.
  • A detailed Sinnoh region Pokédex.

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