Baeg-nyong (BN) Cave CZO was established to make clear in the mechanisms of organic and iorganic materials transfer from surface to subsurface environments at the karstic limestone area. This CZO is going to carry out the monitoring works for local climate, water, minerals and microbes in both of surface and cave inside monitoring position. The sedimentary rocks along the Dong River are composed of Lower Paleozoic Joseon Supergroup, Upper Paleozoic Pyeongan Supergroup and Mesozoic Bansong Supergroup. The carbonate rocks surrounding the cave are composed of the Maggol Formation which belongs to the Joseon Supergroup. The Formation is composed of limestone and dolomitic limestone which was deposited in the supratidal flat during the Ordovician. Baegnyong Cave mostly shows horizontal passages, which have developed along the east-west direction. This cave contains one main passage and three branches. The total length of the cave is about 1,875 m. Except for the few passages which are influenced by input of Dong river water, most passages show more or less constant temperature range (11.0~13.5 ℃) and humidity ranges from 70 to 100 %. Most of the passages show domal in cross section showing the typical shape of vadose passage, even though other shapes are also observed. This cave has been mostly developed along joint planes, whereas some parts of the passages were influenced by strike directions of bedding planes. (Pyengchanggun, 2006, “Scientific investigation of the Baegnyong Cave”) This CZO is supported by Basic Research Laboratory Program from Ministry of science, ICT and future planning.