The area around Doma castle, the tumbleweeds give out 10,000EXP each, with the growth egg its 20,000.
the only catch is only being able to use 1 character, otherwise the 10,000 is split
I messed up by swapping my Hyper wrist for a Celestriad.
however i have come to the conclusion that equipping Terra and Celes with Soul of Thamasa and Celestriads, and Locke and Edgar with Hyper wrists and Master scrolls would be kick ass.