© UnknownGreat Wall of China
For years, British explorer William Lindesay's inquiries about a possible extension of the Great Wall in Mongolia turned up nothing, but the researcher recently had a breakthrough. Seeking insight from Professor Baasan Tudevin, a lauded but hard-to-find expert on the region, Lindesay posted an advertisement in a local newspaper. It was a long shot, but the two connected and the Mongolian geographer said he knew of several such structures in the Gobi desert, the Telegraph reports.

Lindesay formed an expedition in August and with two Land Cruisers, 44 gallons of water, 12 gallons of extra gasoline and a lead from Google Earth, began poking around about 25 miles from the sensitive Chinese-Mongolian border. Two days into the exploration, his team discovered what is thought to be the first section of the Great Wall to exist outside of China. Lost for nearly 1,000 years, the wall's 62-mile-long arm is made mostly of shrubs and dirt. Lindesay told the Telegraph much of the wall is about shin-level, but there is also a stretch that reaches up to his shoulders.

At first, Lindesay thought the section was built around 120 B.C. during the Han dynasty. However, carbon testing placed the remnants in the 11th or 12th centuries. "Overall, the Wall of Genghis Khan in ömnögovi appears to be a missing piece of the Han Dynasty Great Wall which was routed through the heart of the Gobi around 115BC," Lindesay told the Irish Times. Lindesay theorizes that Ghenghis Khan's third son, Ogedei Khan, built the wall to put a stop to gazelle migration from China.

Fascinated by the Great Wall since his first trip to the region in 1986, Lindesay has made a career out of exploring and conserving it. "I have been looking at this area since 1997, when a friend gave me a copy of an atlas showing the red lines of Genghis Khan's attacks and counter-attacks, and underneath those are the strands of wall," Lindesay, told the Telegraph.

The explorer was awarded the rank of O.B.E. (Officer, Order of the British Empire) in 2006 and is the author of several books including The Great Wall Revisited: From the Jade Gate to Old Dragon's Head and Alone on the Great Wall.