The bridge was first mentioned in the ancient Indian Sanskrit epic Ramayana of Valmiki.[4] The name Rama's Bridge or Rama Setu (Sanskrit; setu: bridge) refers to the bridge built by the Vanara (ape men) army of Rama in Hindu theology with instructions from Nala,[5] which he used to reach Lanka and rescue his wife Sita from the Rakshasa king, Ravana.[4] The Ramayana attributes the building of this bridge to Rama in verse 2-22-76, naming it as Setubandhanam, a name that persists until today.[6] The sea separating India and Sri Lanka is called Sethusamudram meaning "Sea of the Bridge". Maps prepared by a Dutch cartographer in 1747, available at the Thanjavur Saraswathi Mahal Library show this area as Ramancoil, a colloquial form of the Tamil Raman Kovil (or Rama's Temple).[7] Another map of Mughal India prepared by J. Rennel in 1788 retrieved from the same library called this area as "the area of the Rama Temple", referring to the temple dedicated to Rama at Rameswaram.[8] Many other maps in Schwartzberg's historical atlas[9][10] and other sources such as travel texts by Marco Polo call this area by various names such as Sethubandha and Sethubandha Rameswaram.[11][12][13][14][15] The western world first encountered it in "historical works in the 9th century" by Ibn Khordadbeh in his Book of Roads and Kingdoms (c. 850), referring to it is Set Bandhai or "Bridge of the Sea".[16] Later, Alberuni described it. The earliest map that calls this area by the name Adam's bridge was prepared by a British cartographer in 1804.[2][4][17] Some early Islamic sources refer to a mountain in Sri Lanka as Adam's Peak, where Adam supposedly fell to earth and describes Adam as crossing from Sri Lanka to India on what became known as Adam's Bridge.[