Raxxla
"'Raxxla!' Jason said. 'Remember: Raxxla!' Then, as he pushed Alex back into the cramped escape pod, he shouted, 'Remember me, Alex! I wouldn't have wished this on you. Raxxla!'" From the Dark Wheel by Robert Holstock [1]
"It wasn’t even in the game, though that didn’t stop many of us spending hours looking for it… you just never knew, did you? It remains to be seen whether Raxxla will be featured in Elite Dangerous."[2]
Frontier Staff refuse to confirm or deny the existence of this fabled location [3]