Located in the narrowest part of the Al-Ula Valley, the old town of Al-Ula was built at a slight elevation and was once home to nearly 900 homes, 400 shops and 5 courtyards, and still contains the remains of some of the original stone and mud brick buildings, as well as a castle Musa ibn Nusayr dating back to the 10th century and which dominates the city and the nearby oasis.