Anybody Canyon

Echo chamber once mistakenly used as a set for a planet on TNG.

* Origin

Season 1, Episode 4 "The Last Outpost". Riker beamed onto a planet in the Delphi Ardu system and searched for his missing Dustbuster Club who were supposed to have appeared with him. During the search, he came across a "cliff" overlooking a "canyon" and, in attempting to call out for his crewmen, released the quietest echoing yell in all of TV history.