Nizwa Fort
Nizwa Fort was built during the reign of Imam Sultan bin Saif bin Malik Al Yarubi (1649-1679 AD) at the beginning of the eleventh century AH / mid seventeenth century AD. Building the fort took twelve years. Its height is 34 m, and its diameter is 45 m. It serves as a flat-roof platform erected on a base of crushed stones, its height is 15 m and it around 30 m to the ground. It is equipped with cannon holes. The entrance of the fort has a narrow staircase in the form of the letter ح (ح is an Arabic letter equivalent to H in English). It has seven doors, and at each door a turn. These doors have defensive openings at the top.
Nizwa Castle
As for Nizwa Castle, it was built by Imam Salt bin Malik Al Kharusi in the first half of the third century AH / late ninth century AD, and it was built next to the old mosque. Students of knowledge are called Sohar rooms, a headquarters for guests who come from far away to visit the imam, the military room, the imam’s library, coffee making and preparation rooms, prayer rooms in which the imam used to meet with people, a room (al-Najwa) for secret conversation, the imam’s private rooms in which he used to stay for worship, receiving guests, and dates stores. The castle is surrounded by a high defensive wall with gunspots and a small lane for soldiers.