What is the name of the mythical mountain in Zoroastrian cosmology?

The mythical mountain in Zoroastrian cosmology is Hara Berezaiti.

Also called Mount Hara, Hara Berezaiti is an Avestan name commonly interpreted as “High Watch” or “High Guard.” In Zoroastrian tradition, it is a cosmic mountain or range rather than an ordinary geographic peak. Later Iranian texts place it at the center of the world, around which the stars and planets revolve.

The Avesta associates Mount Hara with Mithra, who surveys the lands of the Iranian world from its heights. The later Bundahishn says the mountain rose from the originally flat earth for 800 years, eventually reaching heaven. It was also described as the source of the world’s waters, with the sacred river Aredvi Sura Anahita flowing from it toward the cosmic ocean Vourukasha.

Readers often confuse it with Mount Meru, the cosmic mountain of Indian religions, because both occupy a central place in their respective cosmologies. Hara Berezaiti is also linked historically and linguistically with names such as Alborz, but those modern mountain ranges are not identical to the original mythical mountain.