Fort Pierson was constructed during World War II, along with Fort Direction across the mouth of the river at South Arm. Together they covered the shipping that came to and from Hobart and remained vigilant for any invasion force that might arrive at the River Derwent. Fort Pierson was constructed with one four-inch (102 mm) gun, several huts which housed around 200 men, as well as an observation building and a complicated underground tunnel and concrete reinforced gun emplacement.
The only enemy action to ever affect Hobart happened on 1 August 1942, when a submarine-launched Japanese spy plane flew from the submarine’s mooring in Great Oyster Bay south along the east coast of Tasmania, before flying northward along the Derwent River surveying Hobart and then returning to its mother submarine. Although both emplacements detected the flight, the plane was at too high an altitude to fire upon, and no aircraft were available to intercept it. After this event, two anti-aircraft guns were positioned on nearby hills, but the Japanese never returned to Tasmania again during the war.
The only shots ever fired in anger from a gun emplacement on the River Derwent were in 1940, from the Pierson Battery. This happened because a German ship failed to leave when ordered.
Sections of the fort, such as the observation building and the concrete reinforced gun emplacement, situated on the cliff face, are able to be visited and viewed. Geocache is in a small container with a logbook, pen and swaps. Room for small trackables
*Previous finders please note* Unfortunately cache has had to be relocated due to muggle activity.