- You may be looking for the constellation.
The planet Midnight had a waterfall supposedly made of sapphires. (TV: Midnight)
The Doctor's TARDIS had a "waterfall room" which the Ninth Doctor once directed Rose Tyler to so she could clean herself. (COMIC: Doctormania)
Yaz was once waiting for the Doctor by a waterfall in the "hanging gardens". (WC: A message from Yaz)