Al-Hasa lies in the south of the Kingdom's Eastern Region and is bounded by the Al-Dahna and the Al-Daman deserts. The Al-Hasa oasis is the largest oasis in the Kingdom of Saudi Arabia and the municipality of Al-Hasa constitutes the largest administrative area in the Kingdom.
In ancient times, Al-Hasa was at the center of the trade routes which traders followed between the east of the Arabian peninsula and India, Persia and the Far East.
Al-Hasa has a dry, tropical climate, with a five-month summer and a relatively cold winter. It enjoys the benefit of copious reserves of underground water, which has allowed the area to develop its agricultural potential. Nevertheless, Al-Hasa has to deal with tons of sand, which the wind carries and deposits over the land. To counter this problem, the Kingdom has planted large barriers of trees to prevent the wind-borne sand from damaging inhabited and agricultural areas.