Hwaseong Gojeong-ri Dinosaur Egg Fossil Site

South of Sihwa Lake, red rock islets rise out of an endless reed bed. These rocks yielded dinosaur egg fossils in large numbers, and today a wooden boardwalk lets you walk out and look at real fossil eggs. Until the Sihwa seawall was built this was tidal flat washed by the sea, so the walk shows you traces of both the dinosaurs and a vanished coastline.

Nests uncovered as the sea retreated

The rock layers here are sediments from the Cretaceous period, about 83–85 million years old. Dinosaur eggs and nests were found at six or seven rocky spots that were islands before the Sihwa reclamation. Around 20 nests measuring 50–60 cm across held five or six eggs each, some as many as 12, and about 180 eggs have been found so far. Most dinosaur eggs worldwide come from China and Mongolia, and finding so many in one place is rare, which is why the site was designated a Natural Monument in 2000.

How to spot a fossil egg

The eggs are oval and usually smaller than a fist – 11–12 cm across, the largest about 14 cm. Look for round, greyish cross-sections set into the surface of the red sedimentary rock: that is the eggshell. They are easy to mistake for pebbles, so compare with the photos on the information boards. Besides eggs, the rocks contain plant fossils such as jointed marsh reeds and many trace fossils, suggesting that about 100 million years ago this area was a waterside habitat for dinosaurs.

Walking the boardwalk

The trail starts from the entrance deck beside the visitor centre, is 1,527 m long and takes about an hour. The boardwalk crosses the former tidal flat, now covered in reeds, with a viewing deck halfway. At the far end, among rocky knolls that were once islands, you can see where the eggs are exposed. The whole fossil area covers 15.9 km².

The two-storey visitor centre has a small exhibition about the site and about Koreaceratops hwaseongensis, a horned dinosaur named in 2011 after bones were found in the Tando seawall, also in Hwaseong.

From tidal flat to grassland

The wide grassland around the boardwalk was once tidal flat, washed by the sea. When the Sihwa reclamation drained it, the seabed was exposed – and with it the eggs buried in the rocks of the former islets. The trail map still names those islets, such as Sanghanyeom, Junghanyeom, Hahanyeom and Mumyeongseom, a reminder that this was open sea. Researchers expect more eggs to appear if the remaining mud is cleared away.

Tripto tips

• Opening hours: Tuesday to Sunday 09:00–17:00 (10:00–17:00 in winter). Closed Mondays, 1 January and the Seollal and Chuseok holidays.
• Admission: free. The car park has space for 60 cars and 20 coaches.
• Time needed: 1–2 hours for the boardwalk there and back plus the visitor centre.
• Getting there: the address is 659 Gongnyong-ro, Songsan-myeon, Hwaseong. It is hard to reach by public transport, so going by car is best.
• What to bring: there is almost no shade on the boardwalk, so sunscreen and a hat are essential in summer; in winter the wind is strong, so dress warmly.
• Best time: autumn, when the reeds turn golden, is the nicest season for the walk, and the reed beds look lovely towards sunset.