Introduction to the source water covered by glass: At the source of Fenhe River, there is an antique three-story pavilion named "Fenyuan Pavilion". There is a horizontal plaque hanging on the eaves of the attic on the top floor, which reads "Fenyuan Lingmarsh". The one-foot-square pool in front of Fenyuan Pavilion is the source of the Fen River. The water in the pool is clear and flat, like a mirror; the colorful stones at the bottom of the pool are like clear gems, contrasting with the Fen River.