Kadath...

...is an ancient city and the home of the dream-gods of Earth, otherwise known as the Ancient Ones. Kadath's precise location in the universe is uncertain; there is even confusion over whether it exists in the dream-world or the waking world. However, in Howard Phillips Lovecrafts' At the Mountains of Madness, it is hinted that the mountain ranges beyond the Antarctic plateau of Leng may hide the location of Kadath.