Created from bedrock formed 450 million years ago Ondaldonggul Cave in Danyang

(Natural Monument/National Geopark)

Danyang Ondaldonggul Cave is a limestone cave with a main and branch cave of 700 meters* in length and is documented in the ancient map of Yeongchun-hyun, Chungcheong-do, in the 14th volume of the 'Sinjeungdonggugyeojiseungnam'.
* A 450-meter section is open to the public.

The pale white limestone stalactites and stalagmites are well developed, and most of the paths are horizontal, making it easy to explore. Occasionally, there are areas with three stories, adding an interesting aspect, and there are cave streams along the way due to the abundance of groundwater. Various creatures such as millipedes, centipedes, insects, and mammals live here.

Ondaldonggul Cave is located in Ondal Tourist Park, a tourist destination themed on General Ondal and Princess Pyeonggang, which consists of various facilities such as Samjok-o* Square, the Ondalgwan Museum, where you can get a glimpse of the love story between Ondal and Pyeonggang, local restaurants, and souvenir shops. The Ondalsanseong Fortress is located at the top of Seongsan Mountain, right next to the cave. The drama set in Ondal Tourist Park is famous for filming 'Legend', 'Yeon Gaesomun', and 'Destiny', and the set displays props used in 'Legend' and 'Yeon Gaesomun', and you can take photos with replicas of the characters in the dramas.
* Samjok-o is a three-legged crow that can be found in many Goguryeo tomb paintings. They are usually depicted in a circle, often with peacock feathers, and are characterized as crows about to soar or standing still with their wings folded.

The set of the drama consists of a Chinese-style building modeled after the Luoyang Castle from the Tang Dynasty and the Sui Dynasty of China. The reason for the Chinese style is that most of the dramas about Goguryeo were about wars with China, which required scenes that depicted the situation in the hostile country. Looking for the differences between Korean and Chinese buildings is also another fun thing to do.

If you head towards Yeongwol, there is a place where you can experience rafting on the Namhangang River in Osa-ri, the border area with Yeongwol, so many tourists in groups come here for team-building activities.