The life of Yoda has always been more enveloped in mystery than any other Star Wars character, and at the end of Star Wars: The Clone Wars season 6, the Jedi Master's connection with the planet Dagobah became one of the biggest questions surrounding him. By the conclusion of the original trilogy, Dagobah would be where Yoda's story came to an end, but the first time he set foot on the planet was much earlier. The Clone Wars season 6, episode 11 "Voices" depicts Yoda embarking on a spiritual quest for answers given to him by the Living Force projection of Qui-Gon Jinn that brings him on his first arrival to Dagobah and into a familiar cave.
Qui-Gon warns Yoda of the strength of the darkness within as he enters, descending a flight of manmade stairs and passing through a carved stone arch to reach the cave's center. The cave grants Yoda visions of the looming figure of Darth Sidious and vague clues as to the impending rise of the Sith, but does not give him anything clear enough to prevent the suffering to come. Yoda departed the cave in order to continue his quest, but did not stop to consider the implications of the cave's existence or why the dark side of the Force would provide him aid.