MUTHANNA, Iraq — Lake Sawa in Muthanna province is an unusual oasis in an arid desert, and a mysterious one at that, boasting religious significance and its own version of the Loch Ness Monster.

The salty lake is enclosed, an endorheic basin like the Great Salt Lake in Utah, with no obvious water inlet or outlet. Over time, the area was transformed into a religious site and eventually took on even greater importance to Shiites in the region who believe that when the lake dries out, Imam Mahdi will come to bring justice on Earth and signify that the end of days is near.

Cleric Issam al-Yasiri of Babil, one of Lake Sawa's frequent visitors, spoke to Al-Monitor about what he believes is its history. "This lake is sacred for Muslims who visit it to benefit from its blessings. Its water surfaced on the birthday of Prophet Muhammad in [the year] 571," he said. "Lake visitors should wash their faces with its water and submerge their bodies in it, because this water has been blessed by Allah."

According to Yasiri, this background can be found in Islamic historical tales. "This thousands-of-years-old lake has never dried out despite its desert location. It has no tributary … and rainwater is rare," he said.