Holon Grasslands
From The Pokemon Insurgence Wiki
The Holon Grasslands is north of Settlement Foxtrot and west of Settlement Oscar.
Delta Mawile can be found in a hidden grotto north of the Heart Swap statue (to the west of the Painter).
Delta Treecko can be summoned via a buzzer on the northern edge of the map ('Start Workout').
In the northeast there is a flower patch where you can encounter a Combee. There is also a rare candy hidden behind a tree on the left.
