Abaddon

Geography

Starting more than 500 years ago, Abaddon is the largest volcanic event in all of Holocene as well as the longest lasting single event. Abaddon covers a colossal region east of Jorantes, north of the fromer Sarpadian Empire and west of Yavimaya. There has not been a single day in 500 years that lava has not flowed freely somewhere within Abaddon.
More than 500 years ago, the area now covered by Abaddon was a the central highlands of north-eastern Zara comprising a series of rising plateaus, hills, lush wilderness with the Kossuth Mons volcano at it's centre.
At more than 6kms tall, one day Kossuth Mons massiviely erupted and triggered a series of events that cracked the surface of the world around it. From that point one, volcanoes rapidly appeared across the former plateau alongside fissures leaking lava and sproradic lava fountains erupting seemingly from nowhere. 
The eruption was so vigorous and extreme that the sun was greatly diminished and periodically blocked for more than a decade, leading to widespread famine and further chaos.
The more vigorous and fountains have become rarer as the centuries have passed while effusive eruptions pouring directly from open vents are now the most common form of eruption. At present the region is laregly bare of vegetation, toxic near some vents that spew poisonous gases rather than lava and dangerous as volvanic activity is unpredictable with the refular formation of cracks in the ground at random points from which a curtain lava will flow.

Localized Phenomena

Unsuprisingly fire loving creatures have settled in the area, adding a further dimension of danger to any travellers. Gateways to places such as the Elemental Planes of Fire and Earth are routinely reported, including one that directly leads to the City of Brass that appears periodically to a schedule only undrestood by certain arcanists sepcialising in a study of the planes.

History

The impacts of the eruption were devastating with the near total destruction of creatures and wilderness within 50kms of Kossuth Mons and deadly destruction further out.  The eruptions continued and spread until all creatures and people previously living in the region were forced to flee if they weren't incinerated first.  Many survivors fled eastwards, settling in the sparcely populated Radiant Coast region, giving a sudden boost in population to a previous remote and obscure region.
Many historians link the fall of the Sarpadian Empire to the eruptions.

Kossuth Mons

A standing gate to the Elemental Plane of Fire begins to form 

Type

Badlands

Location under

Hadean