Monomorph snakehead walnut. Wan Wen walnut is a kind of walnut with collection value, which is formed by special types and characteristics. It requires deep and clear texture, and each pair of Wan Wen walnuts should have similar texture, the same size and the same weight. 990 yuan is the most expensive walnut in Wan Wen. In China, Wan Wen walnuts are mainly concentrated in North China, Northwest China, Northeast China and Southwest China. Among them, the quality of Wan Wen walnut in Beijing, Tianjin and Hebei is the most outstanding, and it is also the origin of traditional fine varieties.