Jawatha Mosque, located in the village of Al-Kilabiyah, about 12 km northeast of Hofuf, Al-Ahsa, 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.
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.
It is also incorrectly spelled Al-Jawana.
Courtesy: www.SaudiBizness.com