Mirrormere

The Mirrormere was the shining lake in the Dimrill Dale beneath the eastern doors of Khazad-dúm, so called because of the stars reflected in its surface. It was called Kheled-zâram by the Dwarves.

Arccording to Dwarven legend, when Durin the Deathless gazed into this pool, he saw seven stars shining above his head. He took this as a sign and began the construction of his realm.