The monument comprises the remains of an emergency coastal defence battery gun emplacement, defending the strategically important port of Cardiff. Located at the south end of Queen Alexandra Dock, the gun house was built from reinforced concrete and red brick and was designed to mount one 6-inch gun. It was originally one of a number of structures defending the harbour.

Source: Cadw scheduling description.

F. Foster, RCAHMW, 31 March 2009