Ryugaiwa Cave, located in Hamamatsu City, Shizuoka Prefecture, is one of the largest limestone caves in the Tokai region. It stretches for approximately 1,000 meters, of which approximately 400 meters are open to the public. Visitors can safely explore the mysterious underground world along well-maintained pathways. The average annual temperature inside the cave is 18°C, making it cool in the summer and warm in the winter, making it a pleasant place to explore in any season.

The various stalactites and stalagmites formed over an incredibly long period of time are illuminated, creating a mystical atmosphere. A particular highlight is Japan's largest underground waterfall, known as the "Golden Falls," which has a drop of approximately 30 meters and abundant water. Its powerful sound and the spectacle of splashing water captivate visitors.

Outside the cave, there is a museum where you can learn about the workings of the cave, and a rest area called "Yokita Cave," where you can enjoy a cool breeze. There are also plenty of restaurants and souvenir shops using local ingredients in the surrounding area, so you can enjoy these activities before or after your cave exploration. This is a recommended spot for family summer vacations and for those who want to experience the mysteries of nature.