Eternal Flame Falls

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At the base of a waterfall deep in the forests of the state of New York a flame burns. A small grotto between the layers of shale protects this fire. Although the name suggest otherwise, the flame isn't eternal. This is a natural phenomenon but the flame occasionally needs a helping hand.
The area around the Eternal Flame Falls does have a different aroma to the surrounding forest. It is natural gas seeping from the layers of shale. Most dissipates in to the air but some of the gas, enclosed by the grotto, is concentrated enough to burn.