Pokemon BDSP Grand Underground Guide

Grand Underground is a cave located beneath the Sinnoh region in Pokemon Brilliant Diamond and Shining Pearl. In this guide, we’ll be discussing all the features included in the Grand Underground as well as the features removed from it in Pokemon BDSP.

Pokemon BDSP Grand Underground

Grand Underground is an updated and expanded version of the Underground feature in Pokemon Diamond and Pearl. Unlike its previous version, it now consists of 6 distinctive sections that can be entered through different entrances via Sinnoh.

Grand Underground Features

In Pokemon BDSP, not all Grand Underground features are available online. Some of the features are exclusive to solo play, some are available both solo and online.

Below we have listed down all the Grand Underground features and which ones are available either solo or online or both.

  • Digging for Treasure: Available both Solo and Online
  • Building a Secret Base: Available only Solo
  • Pokemon Hideaways: Available both Solo and Online
  • Farming Diglett: Available both Solo and Online
  • Underground Man Missions: Available only Solo
  • Burying Spheres: Available only Solo
  • Unlocking Spiritomb: Available only Online

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Old Man Missions

Below we have listed all the Old Man missions in Pokemon BDSP Grand Underground and how to complete them.

Visit Grand Underground

The Grand Underground is locked by default. To unlock it, you must head over to the Eterna City and interact with the Underground man. The underground man is a bald old man who’s found inside the building, to the right of the Pokemon Center.

Talk to him and receive an Explorer Kit, continued by the tutorial he gives on the various ways to enter the Grand Underground, along with a few missions to complete. You will receive Red Sphere S, Blue Sphere S, and Green Sphere S as rewards.

Dig up Treasure or Spheres

In the next mission, you will need to dig up treasure. It will be a mini-game, and you will have to use the red and blue hammers to uncover the selected area.

Switch between the hammers by pressing R. The red (sledge) hammer is for removing the larger rock sections, whereas the blue (pickaxe) hammer is useful for clearing small rocks and thin walls.

Your goal will be to find all the treasures inside the walls before they collapse. You will be Rewarded with Digger Drill for completing this mission.

Create a Secret Base

When facing any wall of the Grand Underground, use a Digger Drill from the Traps menu to drill a hole through it to build a Secret Base.

A player can only have one Secret Base at a time. The old base will be demolished if a new one is built. Rewards received for building a secret base will be Square Pedestal XS and Sturdy Pedestal S.

You can decorate your secret grand underground base with statues that you get through digging. The statues you place will affect what Pokemon will appear for you in Pokemon Hideaways.

Visit Another Player’s Secret Base

For this quest, you simply have to visit the Secret base of any other player. You will receive Round Pedestal M as a reward for finishing this step.

Find a Light of a Different Color

This is similar to the previous one and involves going online to connect with other players. Find other players digging for treasure. There’s a distinct shining blue spot when other players dig, if you dig in that specific spot to help them out, you will complete the quest.

Talk to the Old Man to complete the quest and claim Clear Pedestal L and the Ability to Dig more Treasures.

Grand Underground Map

We have included a map that shows the Grand Underground Map in its entirety. On your switch, press the Right Joystick to zoom out from the map.

Getting a zoomed-in look on your map is a hassle. Here is a quick introduction on how to go about the task:

  • Arrive at the Grand Underground
  • Press the Y button.
  • Select the Grand Underground Map. This map will stay on screen until you manually minimize it. It is helpful if you are lost or need a focused pathway for a certain Hideway.
  • As for the Icon of an Elemental Type on the bottom right, it indicates the increased chance of encountering a Pokemon respective to the image displayed. This also connects to the Pokemon Statue installed within your secret base. In this case, there is an increased chance of encountering a Dragon-type Pokemon.
  • Pressing B will minimize the map

How to Dig in the Grand Underground

The first feature is Digging, which was originally used in the retro Pokemon games. This feature allows you to dig inside the cave and find Treasure.

This is basically a mini-game where you’ll dig for Treasure such as Fossils, Spheres, or Statues. To do so, simply use a Sledgehammer or Pickaxe.

The Sledgehammer is used to dig larger portions, whereas the Pickaxe takes out smaller parts of the rocks. Both have their own duties, and to change the weapon of your choice, simply press R.

However, when digging, make sure to complete the Treasure Hunt before the crack reaches the left side as the wall collapse once it does.

How to Build a Secret Base in the Grand Underground

Another feature is drilling your own secret base within the cave. The base can be created via a Digger drill found in the Traps menu.

Just drill through the wall you like and create your secret base. You can further decorate your base with the Treasure you found, such as the Pokemon Statues, which then dictates what Pokemon will be a part of the Hideaways.

However, you can’t create more than one secret base. If you do, the previous base will be destroyed.

How to Acces Areas in Grand Underground

Let’s talk about accessing the many areas and hideaways available in the Grand Underground.

You will find that there are a total of six sections in the Grand Underground. Written below are methods on accessing each area and what you should expect there

Main Area

This is the starting area that you spawn in once you are given the Explorer Kit in Eterna City.

Pokemon BDSP Grand Underground Hideaways

Within the sprawling cave systems, the following hideaways can be divided from it:

  • Spacious Cave
  • Grassland Cave
  • Fountain Spring Cave
  • Rocky Cave
  • Swampy Cave
  • Riverbank Cave
  • Volcanic Cave
  • Sandsear Cave
  • Dazzling Cave
  • Still-Water Cavern
  • Big Bluff Cavern

Central Area

You can access this area near Celestic Town.

Within this area, you can access the following Hideaways:

  • Dazzling Cave
  • Icy Cave
  • Stargleam Cavern

Top-Left

To enter this area, it is best to enter the Grand Underground Map from Snowpoint City or nearby its area.

Pokemon BDSP Grand Underground Hideaways

Within this area, you can access the following hideaways:

  • Whiteout Cave
  • Icy Cave
  • Dazzling Cave
  • Spacious Cave
  • Glacial Cavern

Bottom Left

Using the Explorer kit near or within Twinleaf Town, Canalave City or Ramanas Park will lead you to the Bottom Left area of the Grand Underground Map.

Pokemon BDSP Grand Underground Hideaways

Within this area you will find the following caverns:

  • Spacious Cave
  • Grassland Cave
  • Fountainspring Cave
  • Swampy Cave
  • Riverbank Cave
  • Sunlit Cavern

Bottom Right

Digging under Sunnyshore City or near it will lead you to the Bottom Right section of the Grand Underground Map.

Pokemon BDSP Grand Underground Hideaways

You will find the following hideaways within this section of the Grand Underground

  • Spacious Cave
  • Rocky Cave
  • Fountainspring Cave
  • Swampy Cave
  • Sandsear Cave
  • Bogsunk Cavern

Top Right

Unfortunately, you can only reach the top right area of the Grand Underground during post-game. You need to dig near or within the Battle Zone which is located to the North-East of the Sinnoh Region.

You can find the following areas within this section of the Grand Underground:

  • Spacious Cave
  • Grassland Cave
  • Fountainspring Cave
  • Rocky Cave
  • Swampy Cave
  • Riverbank Cave
  • Volcanic Cave
  • Sandsear Cave
  • Dazzling Cave
  • Still-Water Cavern
  • Big Bluff Cavern

Grand Underground Pokemon Encounters

Sinnoh League Pokemon

  • Absol
  • Aipom (after getting HM Defog)
  • Barboach
  • Swablu
  • Swinub
  • Tentacool (after getting 7 Gym Badges)
  • Tentacruel (after getting 7 Gym Badges)
  • Togepi
  • Bidoof
  • Bibarel (after getting HM Strength)
  • Bronzor (after getting HM Strength)
  • Budew
  • Buizel
  • Gabite (after getting HM Waterfall)
  • Gastly
  • Gastrodon
  • Geodude
  • Elekid (exclusive to Brilliant Diamond)
  • Gligar (exclusive to Brilliant Diamond)
  • Murkrow (exclusive to Brilliant Diamond)
  • Scyther (exclusive to Brilliant Diamond)
  • Silcoon (exclusive to Brilliant Diamond)
  • Gible (after getting 7 Gym Badges)
  • Girafarig (after getting HM Defog)
  • Glalie
  • Golbat (after getting HM Strength)
  • Graveler (after getting HM Defog)
  • Hippopotas (after getting HM Defog)
  • Hoothoot (after getting HM Strength)
  • Houndoom
  • Buneary
  • Cherubi
  • Chingling (after getting HM Strength)
  • Combee
  • Croagunk
  • Magby (exclusive to Shining Pearl)
  • Wooper (after getting HM Defog)
  • Wurmple
  • Zubat
  • Duskull
  • Kadabra (after getting HM Defog)
  • Kricketot
  • Lickitung
  • Luxio (after getting 7 Gym Badges)
  • Magnemite
  • Onix
  • Pinsir (exclusive to Shining Pearl)
  • Pachirisu
  • Pelipper (after getting 7 Gym Badges)
  • Ponyta (after getting HM Strength)
  • Psyduck
  • Quagsire (after getting HM Defog)
  • Ralts
  • Roselia
  • Rhyhorn
  • Shellos
  • Shinx
  • Skorupi
  • Teddiursa (exclusive to Shining Pearl)
  • Machop
  • Machoke (after getting HM Defog)
  • Mantyke (after getting HM Waterfall)
  • Meditite (after getting HM Strength)
  • Mime (after getting 7 Gym Badges)
  • Munchlax (after getting HM Defog)
  • Octillery (after getting HM Waterfall)
  • Smoochum
  • Sneasel (after getting 7 Gym Badges)
  • Snorunt
  • Snover (after getting 7 Gym Badges)
  • Whiscash (after getting HM Waterfall)
  • Wingull (after getting HM Defog)

National Pokedex Pokemon

  • Aron
  • Aridos
  • Baltoy
  • Banette
  • Beldum
  • Bellsprout
  • Bulbasaur
  • Cacnea
  • Cacturne
  • Camerupt
  • Carvanha
  • Charmander
  • Chikorita
  • Chimchar
  • Chinchou
  • Clamperl
  • Corphish
  • Corsola
  • Crawdaunt
  • Cubone
  • Cyndaquil
  • Oddish
  • Paras
  • Phanpy
  • Piplup
  • Pineco
  • Poliwag
  • Poliwhirl
  • Poochyena
  • Primeape
  • Qwilfish
  • Ralts
  • Squirtle
  • Staryu
  • Sunkern
  • Surskit
  • Tangela
  • Tangrowth
  • Tauros
  • Torchic
  • Torkoal
  • Totodile
  • Caterpie (exclusive to Brilliant Diamond)
  • Dewgong (exclusive to Brilliant Diamond)
  • Ekans (exclusive to Brilliant Diamond)
  • Growlithe (exclusive to Brilliant Diamond)
  • Kecleon (exclusive to Brilliant Diamond)
  • Larvitar (exclusive to Brilliant Diamond)
  • Mawile (exclusive to Brilliant Diamond)
  • Nuzleaf (exclusive to Brilliant Diamond)
  • Pupitar (exclusive to Brilliant Diamond)
  • Lotad (exclusive to Shining Pearl)
  • Lombre (exclusive to Shining Pearl)
  • Lunatone (exclusive to Shining Pearl)
  • Sableye (exclusive to Shining Pearl)
  • Sandshrew (exclusive to Shining Pearl)
  • Sandslash (exclusive to Shining Pearl)
  • Sealeo (exclusive to Shining Pearl)
  • Seviper (exclusive to Shining Pearl)
  • Shelgon (exclusive to Shining Pearl)
  • Slowpoke (exclusive to Shining Pearl)
  • Spheal (exclusive to Shining Pearl)
  • Vulpix (exclusive to Shining Pearl)

How to Find Pokemon in Grand Underground

Below we have listed all the Pokemon that you encounter in the Grand Underground according to their Hideaway spots.

Big Bluff Cavern Hideaway Pokemon Encounters

  • Scyther (exclusive to Brilliant Diamond)
  • Pinsir (exclusive to Shining Pearl)
  • Absol

Bogsunk Cavern Hideaway Pokemon Encounters

  • Lickitung
  • Gligar (exclusive to Brilliant Diamond)
  • Swinub

Dazzling Cave Hideaway Pokemon Encounters

  • Togepi
  • Houndoom
  • Smoochum
  • Elekid (exclusive to Brilliant Diamond)
  • Ralts
  • Duskull
  • Absol

Glacial Cavern Hideaway Pokemon Encounters

  • Magnemite
  • Swinub
  • Elekid (exclusive to Brilliant Diamond)
  • Teddiursa (exclusive to Shining Pearl)
  • Swablu
  • Snorunt
  • Glalie

Fountainspring Cave Hideaway Pokemon Encounters

  • Lickitung
  • Togepi (Before post-game, only place it can be found)
  • Ralts
  • Swablu
  • Gible
  • Gabite

Grassland Cave Hideaway Pokemon Encounters

  • Scyther (exclusive to Brilliant Diamond)
  • Pinsir (exclusive to Shining Pearl)
  • Absol

Icy Cave Hideaway Pokemon Encounters

  • Magnemite
  • Swinub
  • Smoochum
  • Swablu
  • Snorunt
  • Glalie

Riverbank Cave Hideaway Pokemon Encounters

  • Lickitung
  • Scyther (exclusive to Brilliant Diamond)
  • Pinsir (exclusive to Shining Pearl)

Rocky Cave Hideaway Pokemon Encounters

  • Rhyhorn
  • Gligar (exclusive to Brilliant Diamond)
  • Teddiusra (exclusive to Shining Pearl)

Sandsear Cave Hideaway Pokemon Encounters

  • Rhyhorn
  • Houndoom
  • Magby (exclusive to Shining Pearl)

Spacious Cave Hideaway Pokemon Encounters

  • Magnemite
  • Lickitung
  • Rhyhorn
  • Houndoom
  • Swablu
  • Absol

Stargleam Cavern Hideaway Pokemon Encounters

  • Togepi
  • Houndoom
  • Smoochum
  • Elekid (exclusive to Brilliant Diamond)
  • Ralts
  • Duskull
  • Absol

Still-Water Cavern Hideaway Pokemon Encounters

  • Lickitung
  • Scyther (exclusive to Brilliant Diamond)
  • Pinsir (exclusive to Shining Pearl)

Sunlit Cavern Hideaway Pokemon Encounters

  • Rhyhorn
  • Gligar (exclusive to Brilliant Diamond)
  • Teddiusra (exclusive to Shining Pearl)

Swampy Cave Hideaway Pokemon Encounters

  • Lickitung
  • Gligar (exclusive to Brilliant Diamond)
  • Swinub

Typhlo Cavern Hideaway Pokemon Encounters

  • Rhyhorn
  • Houndoom
  • Magby (exclusive to Shining Pearl)

Volcanic Cave Hideaway Pokemon Encounters

  • Houndoom
  • Magby (exclusive to Shining Pearl)

Whiteout Cave Hideaway Pokemon Encounters

  • Magnemite
  • Swinub
  • Elekid (exclusive to Brilliant Diamond)
  • Teddiurse (exclusive to Shining Pearl)
  • Swablu
  • Snorunt
  • Glalie

How to Find Diglett or Dugtrio

Throughout the tunnels of the Grand Underground, you’ll come across either Diglett or Dugtrio dropping pink sparkles.

Picking these sparkles increases the rarity of your drops and once you fill your gauge, you have a few minutes during which your chances of finding rare statues, items and even shiny pokemon is increased.

How to Bury Spheres

Burying Spheres is really simple. Just go to the Sphere menu and select bury. Once you’ve buried the Sphere, it grows over time.

There are many types of spheres such as Red, Green, Blue, Prism, and Pale. Out of which, red, green, and blue grow faster than the rest. You’ll see them gradually growing after a few days.

Additionally, you can bury multiple spheres of the same color to get a bigger one even faster.

How to Unlock Spiritomb

To unlock Spiritomb, you must complete a few objectives:

  • Place Odd Keystone in Hallowed Tower
  • Talk to 32 NPCs in Grand Underground
  • Return to Hallowed Tower and battle Spiritomb

Odd Keystone is a hidden item found inside Twinleaf Town. You can get it from the Black Belt trainer on Route 208, or you can simply dig for it in the Grand Underground. Once found, place it in Hallowed Tower on Route 209.

You must talk to 32 different NPCs in the Grand Underground to increase your Tally. Note that characters other than NPCs don’t provide Tally, and that includes Sphere Traders as well.

Lastly, head back to the Hallowed tower to interact with it and battle Spiritomb to unlock it.

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