This might seem like a really odd question but...

Does anyone know the history of this location? It's surrounded by what looks like a square of the Ashlands region but it's right in the West Gash. Is there some history of a burnt-down forest here or something? It just looks really odd on the maps, where did it come from?

Another explanation I thought of was maybe long ago red mountain blew a chunk over there or something?

http://www.imperial-library.info/content/sixth-house-base

These Dunmer Strongholds were built in part to support the Polyproplon (sp?) Travel System. They are arranged in a large circle on the map. Once you have all the Indexes, you can travel from stronghold to another in a large circle. If you just have some of them, then you can travel to the strongholds that you have indexes for.

there is a mod that gives you a master index for transport between all of them but i don't know if it is still in circulation or not.

I know what the Strongholds are, I was curious as to why this one is seemingly in a small pocket of ashland surrounded by West Gash.

To complete the circular pattern. These strongholds were built 1000's of years ago, perhaps the shape of the island was different back then. The Volcano is a recent addition to the island. Perhaps it came after the strongholds were built.

This is a Bethesda official mod, and can be found on their site.

I think maybe it has something to do with the sixth house taking it over? The ash surrounding it might be caused by them, perhaps? Maybe through blight storms or something. (as we know dagoth ur spreads his blessing through blight, so maybe he sent blight storms to this base specifically to transform his followers or something?)

Good point, but Andasreth is filled with bandits who recently killed off members of House Redoran, so maybe the 6th House held it before that?

I just wondered if there's any explanation for this oddity in game. Maybe I'll come up with my own