The Brimgan Empire's territory is split into two: Northern Lakes and Southern Veins.
Northern Lakes was the term associated with all the lakes littering the place while the Southern Veins meant the fibrous root system of mountain ranges. Entrances to the Brimgan Empire existed in multiple passes among the Lotus Range.
Thankfully for Inala, the Boar King had dropped them at the southern entrance. Thereby, when they entered, they arrived at the rear end of the Southern Veins, a point from which multiple mountain ranges diverged.
Unlike typical mountain ranges, the Southern Veins were made of the same porous rock that formed the walls of the Northern Lakes. And the ones part of the Southern Veins, though stable in their structure, released all sorts of gases, most of which were toxic in nature.
Mass Release of 10 chapters tomorrow. Stay tuned~