Fort Campbell was built between 1935 and 1937 and initially mounted two 6-innch Mark VII guns. A third gun was later added.
The fort was named after the Governor and Commander in Chief, Gen Sir David Graham Muschet Campbell. It is a unique fortifications, much like Shing Mun Redoubt in Hong Kong, built about the same time. The battery was deliberately dispersed and had a irregular layout to inhibit areal reconnaissance and attack. The perimeter was was built to look like field boundaries and is totally irregular in shape.
A series of Defence Points, some later converted to Machine Gun Pillboxes, were built into the perimeter wall. See the plan of the fort for more details. These machine gun pillboxes included concrete tables and benches, similar to those built in stone clad pillboxes of that time.
Dead ground around the perimeter was covered by loopholes in the wall.
The eight original Defence Posts are now as follows: