The Dwarves called Moria Khazad-dûm in J.R.R. Tolkien’s legendarium.
Khazad-dûm was the greatest Dwarven realm of the Misty Mountains. Its name means “Dwarrowdelf,” or the Dwarves’ delving, in Tolkien’s constructed languages. The kingdom was established by Durin the Deathless beneath the mountain called Caradhras.
The Dwarves became wealthy by mining mithril, a remarkably light and strong metal found in the depths. Their mining eventually awakened a Balrog, an ancient creature of fire and shadow. The Dwarves abandoned the city after the Balrog destroyed their kingdom, and Orcs later occupied the abandoned halls.
By the time the Fellowship entered Moria, the vast complex was ruined and dangerous. The names Moria and Khazad-dûm refer to the same place, but Moria is the name most often used by the Elves and other peoples after the kingdom’s fall.