Mount Dolmed was a mountain in the Ered Luin.
Fate
Some Tolkienists such as Robert Foster and Karen Fonstad speculate that after the War of Wrath Dolmed was destroyed when the Ered Luin were broken and the Gulf of Lune broke through it.
However, Ronald E. Kyrmse and later Didier Willis independently noted a prominent unidentified mountain exactly on the location of Dolmed in the map of Beleriand as well as Mount Rerir to the north. This, coupled with a reinterpretation of Tolkien's maps, shows that Dolmed at least partially survived the devastation.
Mount Dolmed loomed over the only known pass from Eriador into Beleriand. According to the Dwarves, it was here that the founders of the Broadbeams and the Firebeards established the Dwarven cities of Nogrod and Belegost.
The two cities were established on the Eastern side of the mountain. A little to the Northeast of Dolmed was Belegost, and a little to the Southeast was Nogrod.
In Y.T. 1497, the First Battle of Beleriand was fought between the Elves and the forces of Morgoth. In the end, the Elves were victorious, and the surviving Orcs fled east toward the Ered Luin. There they were met and annihilated by the Dwarves.
Almost five hundred years later, the battle in the Thousand Caves occurred between the Elves of Doriath and the Dwarves of Nogrod. In F.A. 503, after returning from their victory in Menegroth, the Dwarves were ambushed and slaughtered at Sarn Athrad. After the battle, surviving Dwarves climbed the slopes of Mount Dolmed and were waylaid and slain by Ents.