The exact location of the mountain is unknown.
Fauna and Flora
The mountain contained a unique kind of anesthetic mushrooms, that result in strong intoxication if inhaled or consumed, causing the consumer to process incorrectly, similar to the effects of alchohol, which could result in a state of delirium.
While Natsu Dragneel and Happy are camping in the Mount Altana during their training session during Fairy Tail's dissolution, they meet a guild who had stolen Happy's fish. A drugged Natsu gets enraged and quickly defeats them with the greatest ease, destroying nearly the whole mountain.
During Natsu Dragneel's fight with the Mount Altana Guild, the drugged Fire Dragon Slayer knocks out the four Mages with his Fire Dragon's Wing Attack, causing a massive explosion resulting in the complete thaw of the entire mountain.