Kyushu, the most southwesterly island of Japan, was created by the volcano now known as Mount Aso. The tremendous amount of magma that was ejected from Mt. Aso millions of years ago caused the surface of the volcano to cave in, leaving behind the world's largest above-ground active caldera—the circumference of the caldera is around 80 miles.

Tokyo-based photographer Rinko Kawauchi's book Ametsuchi shows photographs made at Mt. Aso over a five-year period. "Ame" means heaven in Japanese and "tsuchi" means earth or ground— thus the word ametsuchi signifies heaven and earth; the universe.

Kawauchi writes: "Through 1,300 years of field burning, human ritual has sustained a beautiful meadow, which cattle graze on, and people in turn receive a bounty from the cattle—an interconnected chain. The ceremonies that are ceaselessly passed down over generations, the habits, traditions, and such things are the product of prayers and wisdom that help people survive."

Here, in preparation for cattle grazing every spring, dried grass on the caldera is burnt, maintaining the area as a grassland.

Fire also plays a part in the annual Aso Fire Festival in March. Writes the Japan Times: "The main attraction is the dai himonjiyaki, an event in which the mountain grass on Ojo peak (one of the five peaks of Mount Aso) is set on fire in order to form the shape of the kanji 'hi' (fire). The 350-meter-tall flaming kanji is the largest of its kind in Japan. This ritual burning is called noyaki, which refers to the practice of setting fire to the plains in order to keep the grass in good condition."

Other parts of the ceremony involve locals burning pine torches while they pray for a rich harvest.

Says Kawauchi, of her experience at the ceremony:

"The force of the flames burning up the vast grassland was far stronger than I had imagined. Witnessing the landscape completely burnt to pitch black, I was seized by the illusion that I myself had burned up. It was a refreshing sensation, as if the self I had been up until that time was no longer—that I had been reborn anew."

Steaming hot water falls, hot springs and a geothermal power plant are some of the features of the volcanic landscape of the Mt. Aso area. Since the recent tsunami, there has been renewed interest in the development of more energy-producing geothermal plants in the Mt. Aso area, despite resistance to industry in the hot spring (onsen) areas. 

The view from the top of Mt. Naka-Dake, at 5,000 feet elevation, is a major tourist destination. Inside the crater, a churning lake bubbles sulfurous gases. Visitors reach the summit by ropeway or car to see the fumes rising from the crater. Since the volcano is still active, bunker-like concrete shelters are provided around the crater, built after a dozen people perished in a sudden eruption some 50 years ago.

All photos from Ametsuchi, by Rinko Kawauchi (Aperture, 2013).