Not many people know that Groudon can be caught in Pokemon SoulSilver. With this article we will explain how to do it: keep reading!
Steps

Step 1. You will need to have a Pokemon close to level 70 that knows False Swipe
False Swipe is sold in the Golden Warehouse and you can teach it to Kingler / Krabby, Cubone / Marowak and many other Pokemon.

Step 2. Once you have beaten the Elite Four and Lance, go to the Kanto region
While you are traveling, you will encounter the National Pokedex.

Step 3. Beat all the bosses of the Kanto gyms
Once you've done that, go to prof. Oak and will give you Rock Climb.

Step 4. Go to Mr
Pokemon and get the red ball.

Step 5. Go to Fiorlisopoli and find the Falesia Entrance
Go down the stairs.

Step 6. Go left until you find a rocky island; use Rock Climb to climb

Step 7. Go inside the cave next to the hiker and you will see Groudon
Check your Pokemon and make sure it is fit to be able to fight

Step 8. You will need to have a Pokemon that knows a state move, for example moves such as Hypnosis, Yawn, Thunder Wave, or any other move that can stop Groudon

Step 9. Use False Swipe until Groudon has only 1 energy and then use a state move
False Sweep will leave Groudon with 1 energy and then the state move will make him unable to attack anymore and easier to capture.

Step 10. Use the Pokeball several times until you catch it
Dusk balls or Ultra balls are the most recommended.
Advice
- The higher your Pokemon's level, the better.
- Paralysis moves are no better than freezing and falling asleep moves - paralysis won't completely block Groudon.
- Master balls have a 100% chance of catching.
- If the battle seems endless, try a Timer ball. Accuracy increases in proportion to the duration of the battle, so it's great for catching legendary Pokemon!