Fleshing out the Brasol Region
by LoZompatore.There is no canon information about this region and also very little fanon.
The most (fan-made) developed regions are those on the coastline of the Addakian Sound and the northern plains, which do not even register as proper Brasol (they fall in the Addakian Sound area) in OldDawg regional divisions map.
I believe that Sturm already summarized all available fanon information in his maps and timelines for Davania.
The mountains of Brasol themselves are barely covered also by fanon, with references to the remnants of ancient races likely living in isolated communities (pteryx, dwarves, gnomes) and other groups possibily more linked with the surroundings (monkeymen, giants, possibly oltecs, elves and halflings).
Mostly for the fun of it, in this prologue of a Threshold magazine article I dropped some new fluff about Braso Mountains by introducing the subterranean rock-men culture of the Horst of Kirak, governed by the foolish prince-priest Paha, which is menaced by the Crystalline Army of geonids led by Isigg the King of the Deeps. I did not provide much other information (the article was about another subject), but nothing prevents further expansion of these hints.
The easternmost part of the mountain range and the eastern plains leading to the Kenathon River were briefly described in the drafting for Platea, with some areas more fleshed out than others (a list of all suggestions by the fan community is available herew).
There is also (this) rather old article of mine which expanded on Alex Benson and Ethan Deneault notes about gnomes of Vulcania, adding some details to the migration of Snartan gnomes across the Pass of Brasol (Hideenwood) in their voyage back to Vulcania (see entries about Snarta III and Snarta IV) and to their interactions with local Pedhart gnomes.
Maybe a possible overarching theme for Brasol mountains could be that of seclusion.
The Brasol Mountains, the Brasol Pass and Hiddenwood cover a huge region of temperate Davania (approximately as big as Norwold + Known World), almost entirely covered with mountains and valleys.
I figure out this region as a labyrinthine complex of high, impassable rock walls, plateaus, glaciers, volcanoes and winding, lush valleys.
The whole hydrography of the area would be a nightmare to map, with most rivers draining to isolated lakes without any real output to the sea (lake freshwater would seep underground and give life to a huge system of caves and tunnels beneath the mountains).
Any valley could potentially host a whole ecosystem in it. Climate may vay widely among nearby valleys based on average elevation and exposition to dominant winds (you can have glacial winds from the antarctic regions, warm wet currents from the Addakian Sound, warm, dry winds from the Aryptian basin and somewhat dry breezes from Pelatan and Platea, just to number a few and not counting local updrafts / downdrafts from the mountains).
Gven the variety of climates and coditions I guess that it is possible that all cultures crossing the region found a suitable spot in the mountains and left there some people who did not want to proceed further (there may also be the Immortals' intervention on it). Such people found shelter in some valley or plateau, adapted to the local conditions and developed their own cultures. Main differece with analogous communitie of the Hollow World would be that such cultures are not static: they will evolve over time, get assimilated by others, or give birth to their own offshot splinter groups.
The relative safety provided by impassable mountains and high plateaus would lead to political fractionation, and it usually comes with the impossibility to host a large self-sufficient community.
Trade among valleys could become a necessity, with the need to establish at least a primitive road network criss-crossing the whole area. The road network would also provide what limited amount of information is available about the external world.
Mountain passes at low altitude would be a most sought commodity, with nearby communities fighting for their control.
Of course, flying creatures (dragons, pteryx) would be at an anvantage in this, and they could be able to establish large domains (like the ancient Golden Empire of dragons) and keep in touch over much longer distances than the valleys inhabitants who are forced to go on foot. Again, some local culture might become airborne by training flying steeds or by other means (if not proper airships, why not hot air baloons or hang-gliders?)
Overall, some real-world inspiration could be taken from the ancient history of mountainous countires like Switzerland, Nepal, Chile, Bhutan, Tajikistan, Lesotho, Armenia, Kirgizistan and so on, a real-world reference list can be found here).