Gadi Sagar is the lake that supplied water to Jaisalmer from the 14C, before the Indira Gandhi Canal took over in the 20C. The access route goes under Tilon ki Pol, a gateway built by a prostitute named Tila, a favourite of a prince. She saved the building from destruction by transforming its upper part into a small temple dedicated to Krishna. In the months following good monsoons, you can hire a pedalo or small boat to take a look around the site.