The Map - What is this? What can we do with this?

So with the new map out I am super stoked on making my project a reality. In a long dead thread I had said I wanted to make a 3D scale model of the world of Runeterra. The map now makes this possible but the biggest challenge still remains; Scale. The scale of the cities and the size of landmarks remain a big question. I've been able visualize most of it using Mt. Targon as a reference seeing it was stated it was the tallest point on Runeterra. Also a big question for the community; What are the western islands just South-West of Demacia?