Alter Aeon Online Help

Keywords are:  'highlands plateau biomes'

There are several kinds of terrain that indicate higher altitudes:

hill     - raised mounds, crags and cliffs, often rocky
mountain - essentially very large hills, also volcanic cindercones and calderas
plateau  - mesas, corries, high mountain valleys and meadows, a flat plain or
           meadow significantly higher than the surrounding terrain, often with
           one more sides with steep slopes

Highland terrains are rich in mineral resources, with wood, herbs and mushrooms
being more scarce.

The 'climbing' skill helps you ascend the steeper parts of highlands more easily,
and the 'moutaineering' skill lowers the movement cost when in such terrains.