Kuwu Bleduk is one of the mainstay attractions in this area, in addition to the source of eternal fire Mrapen, and Reservoir Kedungombo. Objects of interest from Bleduk is bang-bang mud containing salt and ongoing at regular intervals, between 2 and 3 minutes.
Geologically, Kuwu mud craters, craters of mud as the other, is a gas discharge activity in the core of the earth. This usually is methane gas. Kuwu is the only one located in Central Java. Bang-bang mud that occur normally carry also a solution of mineral rich mud from the bottom up. Sidoarjo mudflow floods also caused by the crater of the mud, although for the latter is a higher level of activity.
Mud from the crater the water contains salt, utilized by local communities for use as material for Bleng salt (IPA: / bləng /) traditionally. The trick is to capture water from it into the Glagah Bleduk * (bamboo split into two), then dried.
According to the story from generation to generation circulating among the local community, Kuwu Bleduk * is due to the hole where it connects with the South Sea (Indian Ocean). It is said that the hole was way back Joko Absentminded of the South Sea to the kingdom after defeating King Medang Kamulan Cengkar Gods who have been turned into a white crocodile in the South Seas. Joko Absentminded supposedly can make the hole because he could blossom into a monster that is on condition that he recognized as his son Prince Aji Saka.