"Nestled amid the mountains of Koriyama reside a beautiful series of illuminated limestone caverns. Each chamber is filled with an assortment of colors, ranging in different shades of green, blue, and pink. The caverns were discovered in 1969 and were formed over 80 million years by the flow of underground streams. The entire cave complex stretches more than 9,000 feet (2,000 meters). A little more than 2,000 feet (800 meters) of the caves are open to the public to explore. The path within the caves is mostly platformed, making navigation relatively comfortable. On display inside are spacious chambers, enormous stalactites, and three extremely rare rock formations. Visitors to the cave will find an amazing example of boxwork, a geological formation where minerals project from the cave walls. The other two formations are known as the Christmas Tree and The Silver Frost. The Christmas tree is a type of stalagmite, while The Silver Frost is a rocky column created from dripstones. During the winter months, there is also a small frozen waterfall that can be viewed on route to the mouth of the cave. Just across the car park, one can traverse an intricately designed bridge to visit the Star Village observatory and planetarium." - ATLAS_OBSCURA