In Mount Coronot there is a rectangle pond upper B1F I doubt you know where that is. In Mount Coronot as you are on your way to Snowpoint City/route 216 and 217
the last pond you pass.
Fish there with a old rod
I know its probably confusing
But I really hope you get it.
mt.coronet
on the left of sunnyshore city. a fisherman has feebas
mt coronet
fisher man
Feebas
mt corenet
feebas
a fisher man on route 222 has it
Fishing in Mt. Coronet
its in a lake in mt.cornet, its where all the fog is.
someone on route 222
the foggy bit in Mt.Cornet