The huge Al Jalali Fort, also known as Al Sharqiah Fort, was built by the Portuguese in the 16th century. Interestingly enough, it was once a prison that was converted into a private heritage museum. Being located on the harbour, Al Jalali Fort offers a beautiful view of the entire city of Muscat. The only entrance to this place is through a steep set of stairs at the front, and entry to this castle is through a permit from the Ministry of National Heritage only.