Castle Moelh Ottoman is a large archaeological historical fortress located close to the village of Mowelh, which belongs to the governorate of Duba, In the old days, the Castle Moelh Ottoman was considered one of the main stations of the coastal pilgrimage road, besides being a gateway to the northern gates of the late Islamic times, The Castle Moelh Ottoman was built during the reign of Sultan Suleiman the Law in 968 Hijri, For more than 100 years, she has been considered by historians as one of the major castles of the Kingdom of Saudi Arabia, In this article, we will learn more about this huge historical castle and a precise description of it, as well as the renovation of the castle.