on route 6665
all the Pokemon on route 210 in Pokemon diamond and pearl are ponyta, geodude and if your really lucky you can find onix.
you get horsea on route 226
Route 208 209 210
go to route 210 from Nathan
You can find this Pokemon in route 228.
route 212 and route 229
Not really that rare... in Pokemon Diamond you can find Sunkerns on Route 204
you find them on route 224
you can find stunkys on diamond on route 214.
maybe a Abra and that
Route 214
on route 6665
all the Pokemon on route 210 in Pokemon diamond and pearl are ponyta, geodude and if your really lucky you can find onix.
Route 228 is where you can find a protector.
In Pokemon diamond and pearl the trophy garden is located on route 212. Glad to answer your question!
Pokeradar on route 230