The Hwaseong Fossilized Dinosaur Egg Site was discovered on an island in the tidal plain south of Sihwaho Lake. The island was revealed when seawaters were blocked during a land reclamation project. As the sedimentary layer formed during the Cretaceous period of the Mesozoic Era (dated around 83 million to 85 million years ago) was eroded by weathering, roughly 200 dinosaur eggs in thirty nests were discovered at twelve dig sites. It is anticipated that more fossils will be discovered once a thorough investigation is carried out and more land is reclaimed.
Most dinosaur eggs are oval shaped and dark red. Considering the properties of the fossilized shells, the eggs that have been discovered so far are assumed to belong to four-legged herbivorous dinosaurs with a long neck and tail, and two-legged herbivorous dinosaurs, including the hadrosaur. A wide range of plant fossils were also discovered alongside the fossilized eggs, leading to expectations that the formerly lush environment may yet be restored.

The discovery of the Fossilized Dinosaur Egg Site in Hwaseong has greatly expanded the scope of Korean paleontology; previous paleontological discoveries were exclusively limited to fossilized dinosaur footprints. This significant discovery has attracted many internationally renowned scholars who have visited the site in Hwaseong.