Despite its cave-like structure, the interior is rarely dark

The Crystal Catacombs are huge chambers made of rock and crystal. Prior to the development of Amegakure as a large metropolis, it was a small underground settlement carved out of the rocks by miners. As the miners excavated further, they discovered the beautiful glowing crystals and began to mine them; these glowing crystals are now used as a common light source in the Amegakure. Eventually, the city expanded further, leaving the Crystal Catacombs empty. Although no one lives there today, the ancient sight still stands and functions as a training ground for Shinobi, who tend to find the dry weather nice for a change.