This sacred ground is where the spring of the legendary Hero's Water is located. This magic elixer, when drank restores every last once of the consumer's chakra, and then some. The spring is not available to people who come from outside the village, nor is it allowed to leave the area around the spring. This is because the Takigakure shinobi don't want their "Ace in the Hole" to be spread through to the other countries.