Lumps Fort is a disused fortification built on Portsea Island as part of the defences for the naval base at Portsmouth.
Lumps Fort dates from the time of the Napoleonic Wars. The earliest reference is in the records of the Board of Ordnance in 1805 which mention "Lumps Fort-three 32-pounder guns".
By 1822 the fort was the site of a semaphore station on the semaphore line from London to Portsmouth. It was constructed here to avoid the smog of the town of Portsmouth which would impede direct optical communications from Portsdown Hill. The fort was out of use as a defensive fort by the 1820s and in 1827 part of the fort fell into the sea. The semaphore station was closed in 1847 when the electrical telegraph took over.
The fort was reconstructed between 1859 and 1869 as one of the Palmerston forts in the line of Portsmouth Harbour defences. It became a coastal battery with two 6-inch rifled breech-loader Mk. IV guns. These guns were taken away in 1906, but the fort was rearmed in 1914. It was then a beach defence battery and was armed with a 6-pounder Hotchkiss anti-aircraft gun. At the end of the World War I, it was demolished, leaving only an outline.
Subsequently the borough created the Rose Garden in the remains of Lumps Fort. Adjacent to the site is the Canoe Lake, constructed from a large area of marshland, which was opened on 17 June 1886 and used as a boating lake. The fort also became the site of the Southsea Model Village[