An oasis of dates, renowned springs and the greenest place in the eastern part of Saudi, Al-Ahsa Oasis has more than 3 million palm trees and is the largest palm tree oasis in the world. The magnificence of the Al-Ahsa Oasis has resulted in it being nominated to compete for the title of one of the Seven Wonders of the World.
On the banks of this oasis are many agricultural projects, due to the abundance of water, and freshwater springs. Al-Ahsa acquired its name from the large number of springs it has, for example, Al-Jawhariah, Um Sab’ah, Al-Khodoud and Al-Harah Springs in addition to the sulfur water. It is also known for its great weather.
It was built in the seventh year of hijra (c. 629 AD) at the hands of the Bani Abd al-Qays tribe which lived there before and early in the Islamic period. This mosque is believed to be the first mosque built in Eastern Province and is where the second Friday congregation prayer in Islam was offered, the first being held in Medina. According to legend, when the Hajr Al Aswad, (Black Stone), was stolen from Mecca by the Qarmatians, it was kept in this mosque for nearly 22 years.
Most of the mosque's original structure has been lost and it remains in danger of collapse. Only five small mud-brick arches remain. The visible ruins probably date from around the 9th century AD. The mosque's current structure's design is similar to the design of Masmak fort in Saudi Arabia.