There is a strata of the fossils of the Mesozoic era at the southern foot of Mt Taesong in Pyongyang. It is 2 metres thick and over 100 metres long.
Seen on the surface of the strata is a cyrena fossil weathered with yellowish brown colour. This oval fossil is 2 to 3 cm long.
Also discovered in the strata were traces of fin and plant fossils.
The fossils of the Mesozoic Era of Mt Taesong are under preservation as a natural monument for its significance in studying the evolution of organism in the geological age.