Deep within the mountains of Yamaguchi Prefecture lies Akiyoshido Cave, the longest network of limestone caves in Japan. While the total length of the cavern is nine kilometers (5.5 miles), about one kilometer (0.6 miles) of the cave is open to explore. These chambers are beautifully illuminated and are easily traversed via built up walkways.

There are three entrances to Akiyoshido Cave: the Akiyoshido Entrance, the Kurotani Entrance, or through an elevator. 

The chambers of the cave are decorated with an abundance of stalactites and travertine terraces. Within the cave is a large underground lake, which can be easily enjoyed from the walkway. The water from this lake feeds into a waterfall at the cave's opening. This waterfall can also be admired from the walkway. Towards the end of the caves is a colorfully-illuminated tunnel, this serves as a tribute to the evolution of the human race throughout the ages.

Just outside the caverns are also several hiking trails that wind through the Akiyoshidai Plateau. These trails weave through a hilly landscape littered with fragments of limestone. Some 300 million years ago, the plateau was the site of a coral reef. Over time, the limestone eroded into the formations that we see today.

Akiyoshidai is a wondrous place to visit all year round, with each season presenting the caves from a unique angle.