Moria

  "Durin is the name that the Dwarves use for the eldest of the Seven
    Fathers of their race, and the ancestor of all the kings of the
    Longbeards. He slept alone, until in the deeps of time and the
    awakening of that people he came to Azanulbizar, and in the caves
    above Kheled-zaram in the east of the Misty Mountains he made his
    dwelling, where afterwards were the Mines of Moria renowned in
    song." 

Greatest of the Dwarf-halls, the mansion and folk-home of Durin's Folk, was carved by Durin I early in the First Age in the caves overlooking Azanulbizar. Here is located the tomb of Durin, and here dwelt the heart of his people. Expanded many times, Khazad-dûm finally took up much of the area beneath Barazinbar, Zirak-zigil, and Bundushathur. In the Second Age a tunnel was built to Eregion making it the largest of all Dwarven creations. Khazad-dûm consists of many large halls on a number of levels, as well as mines and much more.

At the end of the First Age, the population of Khazad-dûm was increased, as many skilled Dwarves from the Ered Luin came there after the ruin of Nogrod and Belegost. Early in the Second Age, mithril was discovered in Khazad-dûm, and the friendship between Durin's Folk and the Noldor of Eregion began. The gates of Khazad-dûm were closed during the War of Elves and Sauron, and thus the Dwarves survived through the Second Age.

In TA 1980, the Dwarves, while extending their mithril-mine, relased a great terror beneath Barazinbar. It was named Durin's Bane when the following year it slew two Kings of Khazad-dûm. The Dwarves fled their home never to permanently return. From this time, Khazad-dûm filled with orcs, trolls and foul things. In 2790 Thror was killed by orcs in the city. This led to the War of the Dwarves and Orcs, which ended in 2799 with the battle of Azanulbizar. Despite the Dwarves' victory, Dain Ironfoot refused to re-enter Khazad-dûm because of the presence of Durin's Bane.

As the Kingdom of the noblest Lord of the Seven Tribes, the city was sculpted from rock and embellished by the finest hall-builders of their day. Within its recesses, as well as discovering mithril, the "true-silver", Durin's Folk mined precious jewels and metals. They built stairways to peaks touching the stars, and to depths unknown and terrible. They erected spans across bottom-less pits and enchanting canyons, and fashioned vaults in caves larger than many citadels. Now its chambers are dark and its builders are gone.

Huge and grand, forbidding and mysterious, shrouded by its very nature and with the passage of time, this ancient underground Dwarf-city remains one of the noblest creations in Middle-earth. Many who seek to walk its paths and exploit its untold riches feel the power of its plight and legacy, and must endure visions and terrors beyond comprehension. Moria is both beauty and death incarnate.

The Dwarvish kingdom of Khazad-dûm included Azanulbizar as well as the halls within the mountains. The kingdom is called Phurunargian ("dwarf-delving") in Westron, though more commonly translated as Dwarrowdelf. In Sindarin it was first named Hadhodrond ("Khazad-delving") but the more usual Elvish name, especially after the freeing of Durin's Bane was Moria ("black-pit") from which Men derived the names Black Pit, Black Chasm, and the Mines of Moria.