Also called the Cirith Caradhras, this
passage was used by the first Dwarves to enter Eriador. The pass actually was situated between the peaks of Redhorn and Cloudyhead on the north side and Silvertine on the south. On its eastern side, it dropped into the Dimrill Dale (S. "Nanduhirion"), and travelers could then pass along the western edge of the Elven kingdom of Lorien and into Gondor. The Dwarven city of Khazad-dum lay beneath Silvertine, with entrances on either side of the mountains; Dwarven travelers were be able to take this subterranean route and save time and effort .The pass across the Misty Mountains in the vicinity of Khazad-Dum was named for the highest peak in northwestern Endor. Those not fortunate enough to use the road under the mountains had to travel by this winding and dangerous pass. The Redhorn Gate was blocked by snow during the winter months and was difficult for wagons even in excellent weather. On the positive side, the pass' proximity to the Dwarven folk resulted in very few Orc attacks on those who made the crossing.
A secondary route, the Cloud Pass (S. "Cirith
Faniun"), on the eastern side of the main ridge of the
Hithaeglir, wound between Redhorn and Cloudyhead,
allowing a traveler to avoid the Dimrill Dale. It then
merged with a path along the northern fringe of Lorien
in order to enter the northen part of the vale of Anduin.
Melkor, the fallen Vala, had called upon many Maiar to
aid him in the raising of the Hithaeglir. Unknown and
unknowable to most mortals, one of them was entombed
within the substance of Caradhras. In essence, the
mountain was a sentient being; it was virtually always asleep
and effectively blind and deaf by mannish standards,
but was capable of affecting the substance of its own mass
and the air around it using what mortals would have consider to be magical means. The spirit of Caradhras had
little interest in the events of the world, and typically
undertook to think and act only when prodded by
powerful sorcery. The only grudge it carried was against
the Dwarves who were digging at its roots to obtain the
rare metal mithril. The Khazad were careful not to speak
ill of the mountain while they were working under it or
traveling over it. They kept their mining tunnels
within Caradhras small and clean of debris. It was
considered the best policy among the Dwarves to do
nothing to gain the mountain's attention