Jaisalmer Fort in the Indian state of Rajasthan, a living medieval city within the fortifications, is one of the largest in the world. The city spills down the hillside below the ramparts. It is a UNESCO World Heritage Site. Built in 1156 AD by the Rajput ruler Rawal Jaisal, from whom it derives its name, Jaisalmer was an important caravan sarai, an oasis, on the trade route that connected India with Central Asia, Persia and beyond