Fort Benghisa was built between 1910 and 1912 and was the last of the polygonal coastal fortifications built by the British.
The Fort was initially armed with two 9.2-inch Mark X BL guns and two two 6-inch BL guns. The two pairs of guns were layout adjacent to each other in a continuous gun line. The Fort had three counterscarp galleries to protect the dry ditch, while the West side was a cliff dropping down to the sea.
A Defence Electric Light emplacement was built to the South East of the fort with two searchlights and an engine room and control building.
In the 1950 the Fort was rearmed with three 5.25-inch dual purpose guns, similar to Fort San Rocco. Two similar dual purpose batteries were built in Gibraltar at the same time. These guns were mounted in pits immediately in front of the old 9.2-inch and 6-inch emplacements.