When you are chasing team galactic there, the portal to the distortion world will open, leading you to giratina (level 47) .
If you then talk to the elder in the large house in Celestic town, she will talk about palkia and dialga.
Then when you reach the snowy area on Mt. Coronet, there is a cave with a waterfall in. Go up the waterfall and through the arch, where you find an Adamant Orb and a Lustrous Orb.
Then go back to spear pillar and there will be a crystal rift. Click on it and you will be challenged by Dialga/Palkia (level 70). When you're done with it, go to the exit of spear pillar. go through, then go back again to spear pillar and another rift will be there with the other one, which will also be level 70.
Note: Dialga And Palkia will only appear if you talk to the Elder in Celestic Town.
Thanks
you find arcues
spear pillar is only in Pokemon diamond, pearl, platinum
in spear pillar of course
Get to the top of Spear pillar with the azure flute.
find orbs in the road to spear pillar
go up and find the spear pillar
Spear pillar or it will roam around the sinnoh region.
get the Pokemon platinum guide book
when you have the azure flute you go to the spear pillar and youll find him there
Mt. Coronets Peak
When you are climbing up the mountain to the spear pillar, you will encounter many in the wild.
Dialga is obtainable only in Diamond and Platinum. You’ll need to trade him from Diamond or Platinum to get him in Pearl. You’ll find him on the Spear Pillar (top of Mt. Coronet) in Diamond and Platinum. Dialga can only be caught post-game in Platinum.