Fort Glanville was designed by Governor Major General Sir William Jervois and Lieutenant Colonel Peter Scratchley, both important figures in early Australian colonial defence.

After coming into state government hands in 1951 it was declared as a conservation park and is now managed by the Department for Environment and Water (DEW), preserving and showcasing its historic value.

In the early years of colonial South Australia, the colonists saw themselves as part of the British Empire and external defence as an Imperial responsibility.

[6] Tensions between Britain and the Russian Empire in the 1850s, as starkly demonstrated by the Crimean War, along with Australia-wide moves towards self-government caused a reassessment of the colony's defence posture.

[3] In 1854, Governor Henry Young appointed a commission under Boyle Travers Finniss to report on the defence of the colony, in case of war.

Boyle's report recommended leaving strategic defence in the hands of the Imperial Navy, though South Australia was to purchase a 400-ton naval vessel.

[5] Over time there formed a consensus favouring Semaphore for fixed defences or fortification; a strategy also argued by the government established Hart Commission in 1858.

[9] With no definitive defence policy, in 1864 the government had sought advice from Captain Parkin of HMS Falcon and Commodore Sir William Wiseman commander of the Australian station; both visiting British naval officers.

[8] In 1864, a story circulated, supported by press speculation, that there was a danger of the Russian fleet attacking Melbourne should Russia and Britain find themselves at war.

[10] During the early 1870s South Australia's defence was solely dependent on the volunteer military, and a few artillery pieces purchased during earlier war scares.

[12] The 1877 report, delivered after he became South Australian Governor, called for three batteries, at Largs Bay, Semaphore and Glenelg, connected by a military road and supported by field gun emplacements, naval elements and mobile forces.

[11] He determined that South Australia's most probable defence risk was an attack by up to two ships rather than a larger force, and this formed the basis of the final fortification design.

[12] His report called for Military Road to be extended to Marino, an electro-contact torpedo station be established on Torrens Island and that a gun boat be provided.

Settlement extended beyond Port Augusta, though Adelaide remained the dominant feature in the economy partly due to the layout of the rail network.

[13] The plans were drawn by Alexander Bain Moncrieff of the South Australian Engineer-in-Chief's Department, supervised by Scratchley in his Melbourne headquarters.

[18] Plans for both batteries were completed in June 1878, tenders called for in July and the contract for Fort Glanville awarded in August to John Robb of Kapunda, South Australia for the sum of £15,893 12s 7d.

[26] The fort became the headquarters for the South Australian Permanent Military Force, then the state's entire standing army of one officer and eighteen other ranks.

The unit trained 27 more non-commissioned officers and men who were sent to man the King George Sound batteries near Albany, Western Australia.

[36] Early plans showed the caponier extending from the fort's south west, and a tunnel linking the magazine and southern guns.

[36] Its eastern (outer) wall is not flat, incorporating a design feature known as "hornwork", which opens the field of fire from the rifle holes.

They called for four 9 in (230 mm) 12 long tons (12 t) rifled muzzle-loading (RML) guns, two mounted in turrets and two behind vertical iron shields.

One gun platform and its equipment was rebuilt in 1997 using money raised by Fort Glanville Historical Association volunteers working at the Australian Grand Prix.

In 1895 the South Australian Defence Committee proposed that the guns be mounted at Fort Glanville, replacing the 64-pounders whose siege carriages were then unfit for service.

The Art Gallery of South Australia saved them from a 1941 wartime scrap drive and mounted them on reproduction naval carriages in front of Government House in 1962.

South Australia was experiencing a depression in 1886 and that coupled with a report by General James Bevan Edwards scuttled plans for the third coastal fort.

[34] As early as 1888 the emphasis for defence of the Adelaide coast had already shifted to Fort Largs; a fact cited as part of the reason for abandonment of the Glenelg fortifications.

The decline was also linked to changes in Port Adelaide's maritime facilities and the consequent northward movement of anchored and berthed vessels.

It covers approximately 5 hectares (12 acres) and is bounded by Bower and Military roads, the Point Malcolm Reserve and Semaphore beach.

They act as guards of honour at some Government House functions and attended the restoration opening of the Albany, Western Australia fort, and the annual re-enactment of the Battle of Waterloo in Kyneton, Victoria.

The visitor centre has displays showing the development of South Australia's colonial defence from 1836 and artifacts found on site during restorations.