The Virid and the Green conceptual map (WIP)

[Robulous]

I've been working on this conceptual map of my world, which has two ecosystems: the Green world of human civilisation, and the Virid world, which is seen as toxic, alien and deadly. This is a non-geographical map as most pre-modern maps were: since humans haven't yet explored much of their world, they believe it is literally divided into two mirror hemispheres, one mostly sea with islands, the other mostly land with one large sea.

The Green hemisphere is relatively accurate although distorted, the islands made to look much smaller and more isolated than they are. The "Virid" hemisphere is entirely imaginary, based on myths and folks tales. There's a prevailing attitude that it is foolish and impossible to attempt crossing the oceans (much like in times before Columbus).

It's essentially a cultural map of the world, it just seems a bit empty at the moment so I'd appreciate any suggestions as to how to jazz it up.
Attachment 49342

Btw I got the colours from looking at old maps, some of which were surprisingly lurid!