The western world first encountered it in Ibn Khordadbeh's Book of Roads and Kingdoms (c. 850), in which he refers it as Set Bandhai or Bridge of the Sea. Some early Islamic sources refer to a mountain in Sri Lanka as Adam's Peak, (where Adam supposedly fell to earth). The sources describe Adam as crossing from Sri Lanka to India via the bridge after his expulsion from the Garden of Eden; leading to the name of Adam's Bridge. Alberuni (c. 1030) was probably the first to describe it in such a manner. A British cartographer in 1804 prepared the earliest map that calls this area by the name Adam's bridge.