Lucas and Dawn in the underground of Sinnoh.
The Sinnoh Underground (Japanese: ちかつうろ, Hepburn: Chikatsu Uro, trans. literally meaning; "Underground Passage") is an underground area introduced in the Pokémon Diamond Version, Pokémon Pearl Version and Pokémon Platinum Version. It contains to be an underground area of the Sinnoh region which the player need the Explorer Kit which you can get it from the Underground Man in Eterna City to gain access to the underground. The underground of the Sinnoh region has a lot of fun of discovering items that can't not easily found in the Sinnoh region which exploring in the underground can be compared of being an archaeologist searching for hidden treasures. Luckily, you have to move more with the touch screen instead of pressing the button on the Nintendo DS system. You can create a hidden base and decorate your hideout with different kinds of decorations you obtain.
Basics
The locations of the treasures.
Once entering the Sinnoh underground you can use the buttons to move anywhere around the place. On the top screen of the DS, there will be shining stars seen which gives away a hint that there is a treasure hidden. The player must go to the location where you can tap with your stylus pen once or maybe twice to act like a radar which sees the hidden treasures where you must dig to get them. There are also treasures hidden under the ground but not only that, there are also traps hidden in the underground where you must be careful. Furthermore, there are a lot of sphere's hidden in the underground which the player can trade them for traps or decorations.
Test of the Underground Man
Once you've obtained the Explorer Kit, the Underground Man directly asks you to do a test which you can agree on it or not. If you agree to his tests that he gives you what you must do for him in the Sinnoh Underground and complete one of them, he will give you a reward. The Underground give you these tests and items:
| No. | Missions | Rewards |
|---|---|---|
| 1 | Go to the Underground. | Move Trap (↑), Bubble Trap and Leaf Trap. |
| 2 | Dig up an object. | Prism Sphere 1, Red Sphere 1 and Blue Sphere 1. |
| 3 | Bury a Sphere. | Digger Drill. |
| 4 | Create a Secret Base. | Plain Table, Wooden Chair, Small Bookshelf and Buneary Doll. |
| 5 | Decorate the Secret Base. | A doll Based on your Starter Pokémon. |
| 1 | Obtained the Bronze Flag. | Pretty Gem. |
| 3 | Obtained the Silver Flag. | Shiny Gem. |
| 10 | Obtained the Gold Flag. | Mystic Gem. |
| 50 | Obtained the Platinum Flag. | Glitter Gem. |
Activities
Fossil Dig
Digging treasures.
Fossil Dig is a main activity in the Sinnoh Underground. You can find various of valuable items while searching for fossils. Those items cannot be easily found around the Sinnoh Region while you're not in the Sinnoh Underground. After you've tapped on the wall you can dig out various of treasures. You have two tools to dig out items out of the walls. Those two items are: a Hammer and a pickaxe. Those two items have different level of power which can affect the stability wall to crumble. If you are using the hammer it can let you dig large areas very quickly, but it there is also a catch by using it which it clefts the wall quickly. The pickaxe can let you work at small areas very carefully, but it only increase the cleft in the wall a bit on each time. Each time while you are digging using one of the two items, the cleft meter will let you know how big the cleft actually is. Once the meter is at the left end of the screen, the wall start to collapse.
Items during Fossil Digging
You can find valuable items that cannot be found around the Sinnoh Region that easily. There are six kinds of items that can be found while digging in the underground: Spheres, Shards, Fossils, Evolution Items, Battle Items and Heart Scales. You can trade three of the six treasures to something valuable:
- Spheres — You can give your spheres to one of the three traders in the underground which they will give you a valuable item in return. Those items can be used in your secret base that you have created in the Sinnoh Underground.
- Fossils — Bring your fossils to the Oreburgh Mining Museum which they will restore the fossil into a Pokémon which depends on the fossil that you've found.
- Shards — If you have collected 10 shards of the same color you can bring them to a lady the lives on Route 212. She can give you a TM in exchange which are:
- Red Shard — Sunny Day
- Blue Shard — Rain Dance
- Green Shard — Hail
- Yellow Shard — Sandstorm
Be sure that after you've found an item in the underground that you will put them in the bag before you are leaving the underground. You cannot take your items that you've found in the underground back to the surface without putting them in the bag.
List of Underground Treasures
| Name | Trade | Level | Discovery | ||
|---|---|---|---|---|---|
| Armor Fossil | Blue Sphere | 30 | 50 | E | B |
| Blue Shard | Blue Sphere | 20 | 25 | B | C |
| Blue Sphere | — | 20 | 25 | A | A |
| Damp Stone | Blue Sphere | 40 | 50 | D | D |
| Draco Plate | Red Sphere | 70 | 80 | D | D |
| Dread Plate | Red Sphere | 70 | 80 | D | D |
| Earth Plate | Jade Sphere | 70 | 80 | D | D |
| Everstone | Pale Sphere | 25 | 35 | D | D |
| Fire Stone | Red Sphere | 70 | 80 | D | D |
| Fist Plate | Hard Sphere | 70 | 80 | D | D |
| Flame Plate | Red Sphere | 70 | 80 | D | D |
| Green Shard | Jade Sphere | 25 | 35 | C | B |
| Hard Sphere | — | — | — | B | B |
| Hard Stone | Red Sphere | 25 | 35 | D | D |
| Heart Scale | Red Sphere | 5 | 10 | B | B |
| Heat Stone | Red Sphere | 40 | 50 | D | D |
| Icicle Plate | Blue Sphere | 70 | 80 | D | D |
| Icy Stone | Pale Sphere | 35 | 40 | D | D |
| Insect Plate | Jade Sphere | 70 | 80 | D | D |
| Iron Plate | Hard Sphere | 70 | 80 | D | D |
| Iron Sphere | Hard Sphere | 40 | 50 | D | D |
| Jade Sphere | — | — | — | A | A |
| Leaf Stone | Jade Sphere | 25 | 35 | D | D |
| Light Clay | Jade Sphere | 40 | 50 | D | D |
| Max Revive | Pale Sphere | 40 | 50 | D | D |
| Meadow Plate | Jade Sphere | 70 | 80 | D | D |
| Mind Plate | Pale Sphere | 40 | 50 | D | D |
| Moon Stone | Pale Sphere | 25 | 35 | D | D |
| Pale Sphere | — | — | — | B | B |
| Rare Bone | Pale Sphere | 25 | 35 | D | D |
| Red Shard | Red Sphere | 20 | 25 | C | B |
| Revive | Pale Sphere | 5 | 10 | C | C |
| Skull Fossil | Jade Sphere | 30 | 50 | B | E |
| Sky Plate | Blue Sphere | 70 | 80 | D | D |
| Smooth Rock | Hard Sphere | 35 | 40 | D | D |
| Splash Plate | Blue Sphere | 70 | 80 | D | D |
| Spooky Plate | Pale Sphere | 70 | 80 | D | D |
| Star Piece | Pale Sphere | 35 | 45 | D | D |
| Stone Plate | Hard Sphere | 70 | 80 | D | D |
| Sun Stone | Red Sphere | 25 | 35 | D | D |
| Thunderstone | Hard Sphere | 25 | 35 | D | D |
| Toxic Plate | Pale Sphere | 70 | 80 | D | D |
| Water Stone | Blue Sphere | 25 | 35 | D | D |
| Yellow Shard | Hard Sphere | 20 | 25 | B | C |
| Zap Plate | Hard Sphere | 70 | 80 | D | D |