Ondal Cave (Danyang)

In Yeongchun, Danyang, where the Namhangang River loops through the hills, a limestone cave opens beneath a fortress named after the Goguryeo general Ondal. Ondal Cave is a natural cave estimated to have begun forming as long as 450 million years ago, and was designated a Natural Monument in 1979. Its entrance sits right by the river, so you can see how floodwater has shaped the passages, and outside, the Ondal tourist park adds a historical drama set and the Ondalsanseong Fortress on the hilltop.

From "South Cave" to Ondal Cave

The Joseon-era geography Sinjeung Dongguk Yeoji Seungnam records the cave as Namgul, the "South Cave", and it was also called Seongsangul after the hill above it. Its present name comes from Ondalsanseong Fortress on the summit. Scientific surveys began in 1966; the cave opened briefly in 1975, closed again because of the terrain, and reopened to the public in 1997 after major works.

Inside the cave

The cave is about 800 m long (some sources give 700–760 m). It consists of a main passage running east from the entrance and five side branches, with six larger chambers along the way. Stalactites and stalagmites have formed in places, and because the inner part lies higher than the entrance, clear water constantly flows out towards the mouth. Fish even live in some of the pools.

When the Namhangang rises, river water flows into the cave, and the walls clearly show how the water has carved them over the ages. The temperature stays around 16°C all year, cool in summer and mild in winter.

Ondal tourist park and fortress

The cave lies within the Ondal tourist park, created in 1995. Its drama set recreates about 50 Goguryeo-style buildings, including palaces and a market street, on some 18,000 m², and many historical series and films have been shot here, including Yeon Gaesomun, The Legend, Six Flying Dragons and the film Along with the Gods. An exhibition hall tells the story of General Ondal and Princess Pyeonggang.

On the hilltop above the cave stands Ondalsanseong, a stone-walled fortress with a circumference of 683 m and a national Historic Site. It takes its name from the local tradition that General Ondal of Goguryeo died here fighting Silla. The walls are well preserved, and the view over the Namhangang and the Yeongchun plain is wide. The Danyang Ondal Culture Festival is held in the area around October each year.

Tripto tips

• Tickets: admission to the Ondal tourist park (including the cave) is KRW 6,000 for adults, 4,500 for teenagers, and 3,500 for children and seniors aged 65+; preschoolers are free. Groups of 20 or more get a discount.
• Opening: 1 March to 30 November 09:00–18:00 (last tickets 17:00); 1 December to 28 February 09:00–17:00 (last tickets 16:00). Parking is free.
• Time needed: about 30 minutes for the cave, around 2 hours for the cave, drama set, exhibition hall and fortress together. The fortress is reached by an uphill walk.
• Watch out for: when the river is high, the cave closes for two to three days. In the rainy season or after heavy rain, call ahead (+82-43-423-8820). The cave floor is wet and can be slippery, so wear trainers. Pets and outside food are not allowed in the park.
• Getting there: the address is 23 Ondal-ro, Yeongchun-myeon, Danyang. County buses run from Danyang town towards Yeongchun but are infrequent, so a car is easiest. Guinsa Temple is close by and pairs well with a visit.