Al Rakayat Fort
Al Rakayat Fort, locally also known as Qal'at al Rakayat, lies in the desert some 9 km south of the town of Al Ruwais in the municipality of Madinat ash Shamal in Qatar. Spelling of its name varies; I have also seen it called Rekayat, Rikyat or Arrakiyat. It is situated next to a camel ranch.
When exactly Al Rakayat Fort was built is unsure. Some sources say it dates back to the 17th/18th century but most agree that it was built in the 19th century. It is said to have been built to guard a local source of water.
The fort has a square ground plan but Al Rakayat Fort is different from other desert forts in Qatar in that it has only 1 circular tower and 3 rectangular ones. The fort is built out of irregular coral blocks and adobe, covered with gypsum-based plaster. There is a small building in front of the entrance which was used as a masjid (mosque).
Al Rakayat Fort is freely accessible. But keep in mind that you will need a 4-wheel drive to reach it. I only had a normal city car. With this I drove to the end of a dirt road and then walked some 1.5 km north through the desert. That doesn't sound like much of a distance, but with a scorching sun and 41 degrees Celsius it is. So if you're going to do that too, be sure to bring enough water with you!
Some 3 km to the south lies Al Thaqab Fort. The same means and advice for access applies for that fort too. Both forts are definitely worth the trouble of visiting. I liked them both very much.