Horse Sand Fort is one of the Solent Forts built to defend Portsmouth. Also known as Palmerston Forts or follies, named after the Prime Minister at the time, Lord Henry Palmerston.
The forts were built in the 1860s. Horse Sand Fort, No Man’s Land Fort and St Helens Fort (the latter located nearer to the Isle of Wight), were built first, and the fourth, Spitbank Fort was constructed two years later in 1867.