In 1750 the Board of Ordnance purchased 40 acres of agricultural land from Jane Priddy to construct an earth rampart as part of the defences of Portsmouth Harbour, which were completed in 1756. In 1771 a magazine, office and cooperage were constructed, with Officer's houses and large gardens added in 1777. As the Navy grew in size and importance, Priddys Hard Royal Naval Armaments Depot was one of a network of ordnance yards and gunwharfs to supply war ships with their guns, ammunition and associated services. During the Napoleonic Wars the magazine complex was extended and in 1848 a laboratory complex was built to the south of the office block specifically for testing the quality and condition of gunpowder. In 1861 "C" Magazine was built and in 1879 the largest magazine, "E" Magazine was constructed. During the 1860s the fortifications were strengthened incorporating brick gateways and carponniers after which the site was altered continuously during the early 20th century. The complex was fully utilised during the 2nd World War with the introduction of 2,500 women workers who filled jobs vacated by men on active service, and it was last used for significant naval activity during the Falklands Conflict. Now the Priddys Hard site is home to The Museum of Naval Firepower. The untimely deaths that have happened at Priddys Hard have been as a result of accidental explosions and in one case an unnatural gust of wind, rumoured to be the evil spirit of a convict labourer who died in the same spot. Sightings of many of the past unfortunate souls have been rumoured by former workers of the Royal Navy Armaments Depot over the years including more recently security guards that have looked after the listed buildings. Recent investigations witnessed a set of heavy chains swinging for no apparent reason and a white shadow seen coming into "C" magazine. The area around room 309 is also said to be active in that phantom footsteps have been heard along with a banging noise against a locked door.