South of Gujo-Hachiman town center is the largest network of caves in the region, known as Otaki Limestone Cave. They are incredibly popular with visitors, and the car park and surrounding gift shops and restaurants are buzzing during the vacations and at weekends.
There are two caves, and you can reach the main one by a short cable car ride.
You can reach the cave by train and then taxi.
There are no direct public transport links to the cave. From Gujo-Hachiman Station, a taxi takes around 20 minutes.
This cave is generally big enough for taller people to not be in fear of cracking their skull and it is well lit, although there is a lot of water around so the rocks can get slippery.
These caves, having never seen any sunlight, are frigid throughout the year so dress accordingly. It takes about 30 minutes to walk the 700-meter stretch that is open to the public. When you reach the 30-meter high waterfall, you're nearly at the end.
Stalactites are said to grow by around a centimeter a year, so the mind boggles at how long some of these monsters have been developing. Many have grown into recognizable shapes and given names such as “Decorated Cake” or the “Leaning Tower of Pisa.” Others have taken on the metallic red tinge of the elements that have gone into their making.
The second cave is for the more adventurous. Here you are given a flashlight and advised to switch it off once you are inside the cave to more fully experience that utter darkness underground.
It is incredibly creepy and disorienting, feelings intensified by the models of prehistoric men and women lurking around corners to scare the life out of you.