Mard castle Is a historic military fortress located in the city of Dumat al-Jandal in Al-Jawf, and away from the city of Sakaka about 50 km and dates back to the first century AD, and the oldest mention of it dates back to the third century AD, mentioned by Queen Zeba (240 - 274) when the invasion of Dumat al-Jandal and Taima was unable to break into the castle She said: "Rebellion Gen and Azz Ablaq"