Midoriko's cave

Midoriko's cave, commonly known as the, is cave where the Shikon no Tama was created after Midoriko, the all powerful priestess who created the Shikon no Tama, defeated the dragon demon Magatsuhi. The cave is situated near the home of demon slayers and Sango guides Inuyasha and the others to the cave and explains the story behind the jewel.

Trivia

 * In the anime version, but not in the manga, the entrance of the cave is protected by a powerful spiritual barrier, which was believed to be created by Midoriko herself, and even within the Shikon No Tama she was able to maintain the barrier. It is also shown that no one can pass the barrier, unless the one who wishes to enter sympathizes with Midoriko, who regrets creating the Shikon No Tama and the destruction it follows. Also, having evil thoughts inside the cave will cause the person to be immediately thrown out of the cave (as what happened to Inuyasha after thinks to use the Shikon No Tama to become a full-fledged demon. And was noted by Shippō as Midoriko's version of "Sit".