Ondaldonggul Cave, Danyang

Site details

Ondaldonggul Cave is a limestone cave located along the Namhangang River. A waterway flows through the cave year-round, and the area around its entrance is sometimes flooded in summer. The Joseon Dynasty tome Dongguk yeoji seungnam (Geographical Encyclopedia of Korea), mentions a stone cave south of Seongsan Mountain in Yeongchun-hyeon. Other texts, including Daedong jiji (Geography of the Great East) and Songnam japji (Encyclopedic Knowledge of Songnam), refer to the cave by names such as Namgul, Seongsangul, and Yeongchunnamgul. Today, it is known as Ondaldonggul Cave, after the poignant legend of the renowned Goguryeo general Ondal and Princess Pyeonggang, which is associated with a fortress located just above the cave. The cave was open to the public from 1975 to 1979, but was closed for some time after being designated as a Natural Monument in 1979. It reopened in 1997. The cave has a total length of approximately 1.5 kilometers, of which about 450 meters are open to visitors. During a scientific exploration in 2008, about 300 meters of new passageways were discovered inside a waterway section that is closed to the public. Various undamaged speleothems remain preserved there in their original state. Visitors can enjoy the entirety of the Ondal Tourist Area by exploring the cave together with Ondalsnaseong Fortress and a local filming set that recreates the Goguryeo period.