Fort Scratchley

Fort Scratchley, a former coastal defence installation, is now a museum. It is located in Newcastle East, a suburb of Newcastle, New South Wales in Australia. It was built in 1882 to defend the city against a possible Russian attack. However, its guns were not fired in anger until 8 June 1942, during the shelling of Newcastle. The Australian Army left the site in 1972.
The fort was completed on 2 April 1882. It was designed by Lieutenant-Colonel Peter Scratchley, after whom the fort was named and included three 9-in Rifle Muzzle Loader (RML) guns and a casemated battery of four 80 pounders. In 1889 three 6-inch BL and one 8-in BL disappearing gun were installed.

During World War II, the fort was further upgraded with the extension of the Battery Observation Post and provision of Searchlight Directing Station and blast walls were constructed in 1942. The two 6-in BL Mark VII guns fired at the Japanese submarine I-21, which shelled the city on 8 June 1942.(from Wikipedia) 

these guns were the only ones that have been fired in anger. I have added some more images I took today I will go back there on a more sunny day.