This cave system becomes the longest cave in Java, with its maze passages that have a total length of about 17km. There is underground river inside the cave, which formed waterfalls and ponds in some places. Most of cave ornaments are white colour, with a variety of types and sizes. One of rare ornament its "cave pearls". Speleogenetically, that affected by the NE-SW fault, cave was formed when the Wonosari limestone uplifted from the seabed at the beginning of Quaternary time, or about 1.8 million years ago.