From the Setting Guide

Protected to the west by a near-impassible range of mountains, broken only by the city of Basalt, and by the gleaming sea on its remaining sides, the vale is one of the most well-defended regions in the area.

The Vale is one of the wealthiest nations in the region, owing to its expansive mithril mines, as well as its control of the sole source of Alaysium in the region.