Uzuldaroum
In Clark Ashton Smith's "The Tale of Satampra Zeiros", Uzuldaroum became the capital of Hyperborea after the populace left Commoriom. The city lies a day's journey from the former capital. It was the last population center in Hyperborea before glaciers overwhelmed the continent.
In H.P. Lovecraft's At the Mountains of Madness (fiction), the city of the Elder Things is called "a Palaeogaean megalopolis compared with which the fabled...Commoriom and Uzuldaroum...are recent things of today--not even of yesterday".