Fort Monckton Fort Monckton is a historic military fort on the eastern end of Stokes Bay , Gosport , Hampshire . Built to protect Portsmouth harbour at the start of the American War of Independence , it was rebuilt in the 1880s as a Palmerston fort . Today it is the only remaining Ministry of Defence owned fort in the Portsmouth area . Construction . Despite several previous plans which noted the exposed nature of Portsmouth harbour to attack , it was not until the American War of Independence that construction of a defensive fort was started on the site in 1779 . The Governor of Portsmouth Lt . General Sir Robert Monckton told his Commanding Engineer , Lt . Col . John Archer to draw up plans for the defence of Stokes Bay . In 1779 the Gilkicker Sea Mark was demolished to provide clear ground for a new temporary fort , which consisted of a thick earth bank , supported by brushwood fascines . So poor was the structure , that the tents of the billeted soldiers blew away in 1780 , while the site was so exposed that it was used as a sighting point by ships entering Portsmouth harbour . Archer proposed a new permanent structure , which was accepted in July 1780 . Known as " The Fort at Gilkicker " , construction started in September 1780 . However , using civilian and often supplemented by conscript labour , construction speed was slow and the design came under criticsm from Charles Lennox , 3rd Duke of Richmond , who in 1782 was appointed as Master - General of the Ordnance . After Archer was removed from his post in 1783 , in light of the Napoleonic Wars construction was taken over by engineer officer James Glenie , who himself was removed in 1784 . Construction again slowed , and after much more controversy in its design and naming , it was renamed Fort Monckton after the now deceased Robert Monckton , and completed just before the French Revolution of 1793 . Armament . In 1872 the outdated armament was a mixture smooth bore guns : two 8 - inch , nine 32pr , two 24pr , six 18pr , two 12pr all Smooth Bore with two 7 - inch Rifled Breech Loading guns . It was proposed to change this to five 7 - inch R . M . L . guns and six 64pr R . M . L . guns . In 1886 the armament mounted was : eleven 8 - inch S . B . five 7 - inch R . B . L . guns and six 64pr R . M . L . guns . By 1891 the armament had been reduced to six 64pr R . M . L . guns , two on ordinary sliding carriages and the other four on standing carriages . These were mounted two to each of 1 , 2 and 5 Bastions . By this time accommodation within the fort was for eight officers with 70 NCOs and men . There were also quarters for 15 married soldiers . Palmerston reconstruction . Considered too small and old to dominate the key anchorage of Spithead by the 1860 Royal Commission on the Defence of the United Kingdom , they instead opted to build the new Fort Gilkicker and give Fort Monckton a minor defensive role in the defence of Portsmouth harbour . Very little was done to modify the fort during this period apart from reforming the gun positions to take the new armament . The fort was often used as a viewing platform for the fleet reviews as illustrated in the editions of the " Illustrated London News " for 1856 and 1858 . In 1875 , experiments were carried out at Stokes Bay with Wilde ' s Electric Light . The light was placed on the South - west bastion of the fort . More experiments continued with Lime Light and signalling lamps for shore - to - ship communication in July 1875 . The fort was incorporated into the defences of Stokes Bay as an adjunct to the Stokes Bay Lines ; the Royal Engineers moved into the fort in 1878 to train in the use of naval mine s and later search light s . In 1879 , torpedo experiments were carried out at Stokes Bay and part of this consisted of a mock attack on Fort Monckton . This sham attack was recorded in the " Illustrated London News " . The fort was an ideal viewing platform for the observers and members of the public . In 1880 , another demonstration of naval warfare took place in the vicinity of the fort . In 1880 , the 4th Company of Submarine Miners of the Royal Engineers occupied the fort . They moved out in 1884 to Fort Blockhouse , leaving Fort Monckton as accommodation for the R . E . Militia during the annual training . Anti - aircraft searchlights were located in the fort during WW1 and an anti - aircraft artillery unit was quartered in the fort during WW2 . No . 1 Military Training Establishment . Virtually abandoned after WW2 , the fort was however retained by the Ministry of Defence and now remains the only fort in the Portsmouth area retained within MoD ( Army ) — as opposed to Royal Navy — ownership . Located next to the Stokes Bay Golf Course , much of the original fort still exists including the bastion s , sea facing casemates , guard room , one of the caponier s and the ditch . The fort retains its original drawbridge and is additionally protected by modern razor wire security fencing , CCTV camera s and high intensity lighting . The site has been heavily modified with modern offices and accommodation added on and around it . Security at the site is not undertaken by the MoD Police , but by an in - house civilian guardforce . Now referred to as No . 1 Military Training Establishment by the British Army , it is occupied by the Ministry of Defence . In his book " The Big Breach " , former MI6 officer Richard Tomlinson alleges that Fort Monckton is now the Secret Intelligence Service ' s field operations training centre , where both basic and advanced field training is given to SIS personnel . As well providing liaison training with others services including the Special Air Service and Special Boat Service .