Introduction to the Kingdom of Callia: Callia is a woody fern that is a relic of the same era as the dinosaurs. It has a history of 180 million years and survived the catastrophe of the Quaternary glaciers on Earth. Living fossil. The Dinghu Mountain Callia Kingdom is damp and sheltered from the wind. The wild Callia species in the area grow luxuriantly, which is rare in other places.