Deep underground beneath the Wu Shi Academy and guarded by a dungeon filled with traps just outside its entrance, the Dragon Grotto is a natural cavern from which a spring of Earthrealm's lifeforce, the Jinsei, sprung forth. The monks of the White Lotus Society built an effigy of many dragons around the spring, some carved from limestone while more were carved from gold and have the spring pouring from their mouths, to honor the Elder Gods. Many students and residents of the academy above will bring tributes of gold, food, and other items to the spring in reverence of both Earthrealm and the Elder Gods, while the White Lotus Society protects the spring as one of their most well-guarded secrets so that no one of evil intent may harness the power of the Jinsei for their own nefarious needs.
The Dragon Grotto was shown by Kung Jin as he was taking Aiko below the stone slab. He was ecstatic on showing her the White Lotus Society's greatest secret, which was the hidden cavern that housed the Jinsei springs that was originally created from the Sky Temple. Jin told her the monks rotate to keep it away from intruders and evildoers from other realms, as the Jinsei had many healing properties as well as being the lifeforce of the planet itself. Warriors sculptured numerous effigies of dragons honoring the Elder Gods, and they offered them with food, gold, and other sundries. Jin said that Raiden, and other defenders, occasionally rest there after they're wounded from battle.
This location was also the hiding place for all the hapless monks once the Academy got invaded by Kahn's extermination squads. Jin stayed with Liu's grandfather while Kung Lao, Raiden, and Aiko went to Nightwolf's sacred land.
Thankfully, there was little to no damage as the monks and Jin finally emerged once Liu destroyed Kahn. The Jinsei fountain restored its purity once Earthrealm and Outworld restored themselves.
- It's quite possible that the Jinsei was inspired by the Lifestream, the Planet's sacred life force, from Final Fantasy VII. Since it was the sacred cave housing Earthrealm's vitality, and it's used for healing properties, fearing that evildoers could harness its purities, it may be based on the Lifestream as well as the holy lands, even if Shinra and the Sephiroth clones should corrode it and make the Planet suffer.