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O Livro de Mórmon/Geografia/Velho Mundo/Vale de Lemuel
Question: Is there a viable real-world candidate in the Old World for the Valley of Lemuel described in the Book of Mormon?
Several candidates for the "Valley of Lemuel" have been found
The valley of Lemuel requires several characteristics. In 1995, Potter and colleagues found a hitherto unrecognized wadi  which has parallels to the requirements of the Book of Mormon text, including a river of water which is "continually running," which they interpret as requiring a year-round water flow. Although Saudi and US geological surveys have concluded that Saudi Arabia "may...be without any perennial rivers or streams," visits to the area in April, May, July, August, November, December, and January have all found flowing water in the candidate valley which Potter's team identified.
The authors have described the area, with further photographs, in a book. 
While their candidates for the Valley of Lemuel and the River Laman seem truly impressive, other LDS authors have disputed this location for the Valley of Lemuel, suggesting that it is too far from the shores of the Red Sea and that the path required to reach it is implausible. They have offered an alternative based on a different reading of the text's requirements. Chadwick proposes that Bir Marsha, a place easily accessed from the coast of the Red Sea and not far from Potter's candidate, may be more suitable for the Valley of Lemuel, though there may be several other good choices. As for the River Laman, Chadwick believes that it only need have been a wadi flowing with water at the time of Lehi's sermon to his sons, and that it need not flow year round. Lehi said that it ran continuously to the Red Sea, not that it flowed continuously throughout the year, and this can be fulfilled by a path for a wadi that goes into the Red Sea, regardless of how often the path has flowing water. 
- George Potter, "A New Candidate in Arabia for the "Valley of Lemuel"," Journal of Book of Mormon Studies 8/1 (1999): 54–63. off-site [No PDF link] wiki
- George Potter and Richard Wellington, Lehi in the Wilderness: 81 New Documented Evidences That the Book of Mormon Is a True History (Springville, Utah: Cedar Fort, 2003).ISBN 1555176410 off-site
- Jeffrey R. Chadwick, "The Wrong Place for Lehi's Trail and the Valley of Lemuel (Review of: Lehi in the Wilderness)," FARMS Review 17/2 (2005): 197–215. off-site PDF link