Ryugashi Cavern is the biggest cavern in the Tokai district of Japan. It is a 1000 metre long cavern which stretches through a fossil rich limestone layer 359 metres up the south face of Ryugashi mountain in Hamamatsu. Today, 400 metres of the caverns are open to the public. The cavern was formed over millions of years with fossils found inside the caverns carbon dated to 250 million years.
The temperature inside the caverns is a steady 18℃ all year through and this makes it a comfortable place to explore at any time of year.
There are stalactites and stalagmites formed from the limestone which are illuminated with colourful lights and give off a wonderful display. These caverns are still forming and over the last 20 years new formations have developed. Water is abundant in the caverns and the sound of dripping and rushing water adds to the wonderful atmosphere of this place from the distant past. Like a land lost in time, there are fossils and deposits of minerals in the walls of the caverns which are forever suspended in time, and give us a window into the Earths distant past.
The caverns are also home to hundreds of Japan's tiny bats, who aren't at all bothered by the human visitors to the caverns. They can be seen fluttering about in the caverns darting in and out of holes in the formations.
The most spectacular sight is what is termed the "Golden Waterfall," a large waterfall that plunges down into the depths of the caverns from the ceiling. The roaring of the waterfall and spray from the water reminds us that the caverns themselves were formed over millions of years by this very act - of water finding it's way through the limestone and collecting and depositing calcium one it's way through.
Truly a beautiful and awe-inspiring sight these caverns aren't to be missed, one could spend hours exploring the caverns and enjoying all the natural formations and fossils. There are many signs in both Japanese and English, and there is a clear and safe path to follow while exploring.
At the exit to the caverns are diagrams, photos and dioramas explaining how the caverns were discovered and how they were formed. Also on display are many fossils found in the caverns dating back 250 million years. There is also a shop where you can buy minerals, crystals, limestones, and fossils.