Venessia was a planet visited by the First Doctor.
He was unable to remember whether it was Venessia or Enlandia that was a "strange place" where there was no land, only water and a "peculiar form of crystal ice" that giant eels squirmed beneath; it was the last place where all of the TARDIS instruments gave steady, consistent readings before it did so again onboard the Ark. (PROSE: The Ark)