The ring ground had been turned into rice fields.

It was just after rice planting. The paddies were filled with water. The whole plain seemed to be an enormous mirror shining in the sun and reflecting the volcano and white clouds. “The paddies are in a grid!” Hisaharu said. He had not seen gridded paddies. “How sophisticated but unnatural the paddies are! Straight lines never happen in nature,” a private said. Photo of the rice fields at the ring by Volcano Aso is from: https://www.facebook.com/asodesignfarm/