A naturally occurring powerfully flammable gas produced by the Farseas swamp lands.
Preferred to oxygen by most swamp denizens it is rich in nutrients and geyserparks are typically populated and revered as holy grounds by those who are fortunate enough to reside there.
Methane is harvested by special labourers who risk themselves to handle and transport the volatile resource for those who use it for heating, engines, and flight.
The Kropus company Zepherine is the most prolific producer of methane (until recently).