Akiyoshidai: Japan's Karst Plateau

Akiyoshidai Quasi-National Park, located in Yamaguchi Prefecture, is a captivating testament to the power of time and nature. This expansive karst plateau, the largest in Japan, was once a coral reef in a warm, southern sea approximately 350 million years ago. Over millennia, the coral gradually transformed into limestone, which tectonic activity pushed above the surface. Rainwater, seeping through the soil, sculpted the limestone into the unique karst landscape seen today, characterized by countless limestone pinnacles, sinkholes and caves.The plateau's appearance shifts dramatically with the seasons. Spring and summer bring vibrant green grasslands, while autumn paints the landscape in reddish-yellow hues. In winter, the plateau is covered by snow. Akiyoshidai is also known for the annual yamayaki (grass burning) in February, a dramatic event where the dry grasses are burned off to prepare the fields for new growth.Beneath the surface of Akiyoshidai lies Akiyoshido Cave, a vast limestone cave system stretching nearly 9 kilometers. Approximately one kilometer is open to the public, featuring paved paths, bridges, and ample lighting for easy exploration. Inside, visitors can marvel at diverse natural formations, including terraced limestone pools, underground waterfalls, and stalactites and stalagmites.