there is only the sinnon region is Pokemon diamond
There is only one region in Pokemon diamond.
No, there are no other regions in Pokemon Diamond.
there is no way to
No.
You can't. But you could migrate from diffrent regions
The Sinnoh region is the only region in Pokemon Diamond, although the area in the northeast of Sinnoh is like a mini-region.
If you mean Pokemon Regions then the answer is no! There are only 4 games with 2 regions and that's Pokemon: Gold, Silver, Heart Gold and Soul Silver!
Unfortunantly you cant go to other regions in Pokemon diamond and pearl. its not like leafgreen,firered,gold,silver and crystal version where you travel to different regions. You can't, Sinnoh is the only region available in the game.
Pokemon Diamond and Pearl starts in the Sinnoh region and doesn't allow the player to move to other regions. It is considered the fourth generation of Pokemon.
I'm pretty sure because they are in different regions
No, different regions aren't even programmed in the game.
What you have to do is catch all the Pokemon from all the other regions(complete national dex.