If they are at a low level try the cave where you find Roark. If they are higher you could try Surfing or fishing. Also you might try victory road. Or if they are really high the elite four may be your only option.
If they are low lvl (15-) go to stark mountain keep ur low lvl in first place find a wild Pokemon and then switch to a godd Pokemon and beat is easy and zam u have exp for both Pokemon(its awseome i got lvl 1 rioulu 20 lvls up!)
I do not even own that game but the answer is on a lake.
Some people will argue with me but i think the best place to train is at the Pokemon lugue you can battle them over and over again
There are various good places to train flying types in Pokemon Platinum. A good thing to do would be to use the vs seeker.
in heart gold cerulean cave in platinum i don't know
you should train sycher against fire and pshcik pokemon:D
route 205 for Pokemon diamond, pearl and platinum. the trainers have Pokemon from level 10 to level 17
anywhere.
Some people will argue with me but i think the best place to train is at the Pokemon lugue you can battle them over and over again
There are various good places to train flying types in Pokemon Platinum. A good thing to do would be to use the vs seeker.
Personally, I would train a Bird-Type Pokemon at a place where those types of Pokemon is very effective to it. Like Fighting-Types. They are weak to Bird-Types. So, I would train it there!
in heart gold cerulean cave in platinum i don't know
you should train sycher against fire and pshcik pokemon:D
route 205 for Pokemon diamond, pearl and platinum. the trainers have Pokemon from level 10 to level 17
Train Aron.
You train your Pokemon to lvl 100 or you can find some at the battle frontier in the place where you rent Pokemon and select open level in Pokemon platinum
if you have a lv 50 you can train at the Pokemon league my togekiss was lv 50 and now hes a lv 70 in just a couple of minuts
you have to train your girl kirlia
Train it to Level 30