The right spelling is Jawatha not Joatha.

We drove from Hofuf just to see thos wonderful ancient historical lovely mosque about 15 mints. away and it was well worth the time and effort. I have always wanted to see the wonderful mosque. It was like a dream come true!

Here is some info about this small amazing mosque:

Jawatha Mosque (Arabic مسجد جواثا ) (also incorrectly spelled Al-Jawana) is located in the village of Al-Kilabiyah, about 12km northeast of Hofuf, Al-Ahsa, Saudi Arabia. It was the earliest mosque built in east Arabia and most of the original structure is in ruins. The site is still used for prayer.

It was built the in seventh year of hijra (c. 629 AD), around 1230 (13th century) 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 at the Prophet's Mosque in Medina.

The Mosque has been recently renovated and restoration of the surrounding garden and games for children suitable space to spend quality time together with family and children.

The mosque's current structure's design is simillar to the design of Masmak fort in Saudi Arabia.

I recommend you visit this amazing mosque if you were in al ahsa.