Ain Al-Harra

Ain Al-Harra is a natural geothermal spring near Al Mubarraz in the Al-Ahsa Region of the Eastern Province of Saudi Arabia, where geothermal water associated with the deep geological formations of the Arabian Peninsula emerges in the oasis landscape of Al-Ahsa — the world's largest oasis by area, a UNESCO World Heritage Site of exceptional historical and agricultural significance covering over 85 square kilometres of date palm gardens, archaeological sites, and traditional urban settlements in the oil-rich Eastern Province. The spring emerges within an oasis cultural landscape that has been continuously cultivated and inhabited for at least 10,000 years, where the extraordinary density of date palms (over 2.5 million trees), the traditional qanat irrigation systems, and the ancient tells (archaeological mounds) preserving Bronze Age to Islamic-era occupation layers make Al-Ahsa one of the most archaeologically layered oasis environments in the entire Arabian world. The geothermal spring activity at Ain Al-Harra represents one of the natural water sources that made this desert oasis sustainable across ten millennia of human civilisation in an otherwise hyper-arid Arabian landscape.