Act as a seasoned worldbuilder with expertise in crafting unique fantasy ecosystems. Design a land where rivers flow with liquid fire instead of water. Describe the [GEOLOGICAL ORIGINS] of these rivers, the [ADAPTATIONS] of flora and fauna thriving in this extreme environment, and the [CULTURAL IMPACT] on civilizations that depend on this fiery resource. How do inhabitants harness or worship the rivers? What myths or legends surround them? Be vivid and immersive, blending scientific plausibility with fantastical elements.