Musa bin Nusayr Castle, AlUla

قلعة موسى بن نصير is located in AlUla, Saudi Arabia, and its construction dates to the 6th century BCE. Built on a fertile valley site that later formed the core of the old town, the structure is recorded as the oldest building in that settlement.

The site functioned as a fortified position from its earliest phase, benefiting from a commanding perch above the surrounding settlement. Over time the castle was repaired and rebuilt in multiple episodes, with successive works renewing its defensive fabric across different periods. From its prominent position it looked out over the main caravan route that served Hajj convoys, a role that connected the place to long-distance movement and protection of travellers.

The complex acquired its present names through historical association and local tradition. It is called Musa bin Nusayr Castle because it is said that the Arab Muslim commander Musa bin Nusayr stayed there; it is also known simply as Al-Ula Castle, described as the oldest castle in the town constructed of sandstone. In the modern era the monument underwent recent restoration work; subsequent interventions have left the outer walls as the principal surviving element of the monument.