Occupying a central position along the escarpment of the Great Fault, Fort Mosta, or Fort Musta as was its official British designation, was the most strategically placed land fort on the Victoria Lines.  Originally designed as one of three isolated strongholds on the North West Front, the proposal for the construction of Fort Mosta was approved in 1873. The first of the three forts to be initiated was Fort Bingemma, begun in 1875, and to be followed by Fort Madalena in 1878. By the time of Simmons' visit to Malta in February 1878, work on Fort Mosta had not yet commenced. Begun later in 1878, Fort Mosta is a typical example of an British hill fort, consisting of two main component parts, a polygonal enceinte and a focal casemated keep, of a pentagonal plan. The fort occupies the cliff faces on the spur of land at the mouth of Wied il-Ghasri and was built, apparently according to available documentation and some archaeological evidence, on the site of a Bronze Age citadel (De Grognet).