Oh...thanks. so no more classic flat map for me then.Selecting "Sculpted" gives you the mountain top with sculpted terrain at the top of the mountain, selecting "Flat" gives you the same mountain top, but flattened.
The mountain top is the 'skirt' for the South American tropical zoo, basically.
If you want a tropical zoo in South America that is not on a mountain top, you need to use the 'height map' feature. If you want it perfectly flat, you'll just need a heightmap that is perfectly flat.