Landscape of aeons-ago water cave in Hunan

The undated photo shows a boat passes through Mao Cave located in Laifeng County of central China’s Hunan Province. (China News Service/Zhou Xingliang)

The water cave is 58 meters wide and 36 meters high, with a 215-meter swallet stream. It is formed by aeons of the dissolving action of underground water as it seeps through the cracks in limestone.