The Valley of Hell (地獄谷, Jigogudani, English TV: Hell Valley) is a remote canyon located in the Land of Hot Water. Like many areas of the country, hot water naturally flows from the earth and pools in the valley; the water is rich with iron, causing it to turn red. Because of the water's temperature and because of the valley's geography, foul-smelling steam is always thick in the valley. This make it quite inhospitable to life, with no native animals and only minimal plant life.
After the Chinoike clan was expelled from the Land of Lightning, they were forced to settle in the Valley of Hell. When the people of Yugakure checked up on the clan a few months later, they mistook the valley's red water for blood and assumed some calamity had befallen the Chinoike; rather than investigate or offer help, they declared the valley off-limits and, over time, forgot where it was located. In truth, the Chinoike clan was able to survive off the valley's scarce resources and lived peacefully for years. Decades of living so close together eventually became too much for the clan and fighting broke out, with only En Oyashiro and his daughter, Chino, surviving.
A few years after the end of the Fourth Shinobi World War, Oyashiro made plans to turn the Valley of Hell into a hotspring resort.