Spear Pillar, which is at the very top.
If you're playing Diamond, the Pokemon in Mt. Coronet should be Dialga. You have to get the 7th badge before you are able to get to the top of Mt. Coronet where Dialga is though.
Mt. Coronet right behind giratina
ANSWER:At the top of Mt. Coronet in the blue portal.
atop mt coronet is dialga in diamond, palkia in pearl, or both and giratina in platinum.
that's where you catch dialga or palkia
In case you should have a master ball with you because its a legendary pokemon. to get to dialga go to mt coronet. then go all the way to the top of mt coronet. at the top you are in the spear pillar. head straight and you will see dialga. dialga will scream on you into battle. in battle dont kill dialga use your master you have and to capture dialga. Have fun.
Talk to Cynthias grandmother and find the stone that she tells you to find in mt. Coronet then go to spear pillar.
you find it at the top of mt. coronet after you beated every thing at the team galactic HQ in veilstone city.. :) :)
you find dialga in mount coronet
You can catch both Dialga and Palkia. * Get the National Pokédex * talk to Cynthia's grandmother * Go to Mt. Coronet and find one of these two orbs: * ** Adamant Orb for Dialga ** Lustrous Orb for Palkia * Return to the Summit of Mt. Coronet and the Spear Pillar. * There will be a Blue/Pink portal , that you can use to fight Dialga/Palkia
go to mt coronet to catch palkia or dialga
you go and battle dialga