Where is dialgiapokemon platinum?

Answer 1

first you need to defeat the elite 4. when you have go back to mt coronet a get the adament orb & the lustrous orb. you need water fall, surf & rock climb to get it. when you do that, go to the top of mt coronet where you met giratina & there will be 2 portals. a pink 1 for palkia & a blue 1 for dialga. you can then get the 2 legendarys and give them their respective items, the adament orb for dialga and the lustrous orb for palkia. hope it works