In Shirokawa, there is a small limestone cave. To get into it, you have to visit a certain house to have the door to the cave unlocked.
Inside, it seems freezing cold, but strangely, you get used to it quickly. A wet and slippery metal staircase goes up through a narrow tunnel that leads to a series of fantastic orifices in the rock. A flight of bats flies up to check you out. Baby bats can be seen clinging to the walls. I also saw a snake, and thereafter was very careful where I put my hands and feet.