If you aren't to the Elite Four yet I would suggest either SnowPoint city or somewhere around there. Either that of in the water depending on your pokemon, for best results use a rod.
route 205 for Pokemon diamond, pearl and platinum. the trainers have Pokemon from level 10 to level 17
Stark mountain battle about 7 Pokemon then it will be level 73.
Well,Level 70-100 Is A Good Level To Beat The Elite 4.
in the elite 4 It depends if you're playing gold/silver,/ fire red/ Saphire,/ Enerald,/ Ruby/ leaf green, or diamond/pearl
Train your pokemon.
elite 4
route 205 for Pokemon diamond, pearl and platinum. the trainers have Pokemon from level 10 to level 17
Anywhere that u find Pokemon that are close to the shromishes level.
Route 201 or 202 or 203
i trained mine at mt.cornet
iron island or upper level mt coronet
the place where you can breed Pokemon next to heart-home city, that's where i go
Stark mountain battle about 7 Pokemon then it will be level 73.
just train them
You can not find them you can only train them to 50.
train it to level 40 to get bastiodon.
elite 4