《汉书·传·司马相如传上》
上林苑的东方与苍梧郡相接，西方直达西极。苑的南方有丹水流过。紫渊丛在上挞茧的北方流过。
左苍梧，右西极，丹水更其南，紫渊径其北。
Shanglin Garden borders Cangwu County in the east and reaches Xiji in the west. The Dan River flows through the south of the garden. The Zi Yuan Cong flows north of Shangta Jian.