Moria.
Hadhodhrond.
Khazad-Dum
Moria was founded in the first age, Durin the deathless came to Azanulbizar / Dimrill-Dale / Nanduhirion and made himself a home in the caves above Mirrormere. Khazad-Dum lyes in Hithaeglir / the Misty Mountains under Baraz, Zirak, and Shatur which is known as Fanuidhol, Celebdil and Caradhras. There are two ways to Khazad-Dum, one from East through Dimrill Dale and one from the West trough Hollin and The Doors of Durin. Along the only intrance to Moria from the West ran river Sirannon.
In the Second Age ca. 40, came many dwarfs from there ruined cities Nogrod and Belegost in Ered Luin and the population in Khazad-dum exploded, the next 1550 years is the glory years of Moria. In S.A.1697 Sauron roamed Eregion / Hollin, ruined the Elven city Ost-in-Edhil, Celebrimbor was slayn and the doors to Moria was shut, but Sauron couldn`t take Moria and the Dwarves keept on digging deeper until they in T.A.1980 awakened the Balrog who had been asleep deep beneith the roots of the Mountain Baranzinbar / Caradhras. The Balrog killed DurinVI in T.A.1980 and his son Nain I the year after and then the dwarves left Khazad-Dum.
In ca.T:A:2480 Sauron begins to populize Moria with his servants
In T:A:2790 after Smaug had taken the Dwarf-Kingdom ``Under the Mountain`` at the Lonely Mountain came Thror and his companion Nar to Moria and Thror is slain by the Orc Azog in Moria, Nar bring the news to Thrain II. and he gathers all the Dwarfs for vengeance and three years after begins the war of Dwarves and Orcs and it came to the Battle of Nanduhirion in T.A.2799, where the Orcs lost the control of Moria, but Moria was never rebuilt.
The name Moria have gain a sinister sound after the Dwarfs awakened the Balrog in T.A.1980, the elvs call it, as Gimli says in LotR. ``The black pit`` but it was not a black pit in Second age when Celebrimbor wrote the signs at the Western doors and if you look at the roots of the name Moria it says : Mor = Dark and Ia = Void or Room = The Dark Void; NOT a black pit, and there is a difference between black and dark and between a pit and a room, furthermore Celebrimbor surely wouldnt insult the Moria-Dwarves as the was living close together.
Related Links.: Battles.: War of Orcs and Dwarves.