A reserve of fossils is located in Paektho-dong, Sinuiju City, North Phyongan Province.
The strata in the reserve was formed in the Mesozoic era.
The area has been called a group of animal fossils in Sinuiju (Lycoptera-Ephemeropsis-Eosestheria) for the discovery of various species of animal fossils, including Archaeopteryx Coreanicus Fossil, and fossils of Ditomophalangia, Lycoptera, Ephemeropsis, Limnocyrena and Gastropoda.
There are also plant fossils of bracken, horsetail, cycad, ginkgo and conifers, and a fossil which is presumed to be the ancestor of angiosperm.
The reserve is a worldwide large natural monument of great academic significance.