What is the main content of Shan Hai Jing?

As far as I know, Shan Hai Jing is an ancient book in the pre-Qin period and the oldest geography book full of myths and legends. Mainly describes ancient geography, products, myths, witchcraft, religion, as well as ancient history, medicine, folk customs, ethnic groups and so on. It is not credible to say that this book was written by Xia, which is a record of people in Zhou and Qin Dynasties. The book was not written in a moment, and the author was not alone. It was not until the Western Han Dynasty (Xin) that the book was collated that it was co-edited.