Akiyoshido Cave is one of Japan's largest limestone caves, located in Yamaguchi Prefecture. It stretches over 10 kilometers and features stunning rock formations, underground rivers, and unique stalactites and stalagmites. The cave is part of the Akiyoshidai Quasi-National Park, which is known for its beautiful karst landscape. Discovered in 1925, Akiyoshido is a popular tourist destination, attracting visitors with its well-lit pathways and guided tours. The cave maintains a constant temperature of around 17°C (63°F), making it a cool retreat during the summer months. It is also home to various species of bats and other wildlife.