Southsea Castle was one in a series of forts constructed for King Henry VIII, in what was the most ambitious scheme of coastal defence since Roman times.
The castle was built in great haste in 1544, prompted by Henry VIII's fears of a French attack on Portsmouth. It was said to have been designed by the King himself, incorporating the latest continental ideas on the lay-out of artillery forts. It was not long finished when on 18 July 1545, a French invasion fleet did approach Portsmouth and landed on the Isle of White. Henry VIII was at Southsea Castle when the Mary Rose sank next day.
Visitors can still enter the tunnel and see how the Castle would have been defended against invaders.Atrillery, gun platforms and panoramic views from the top of the keep to the Isle of Wight and Solent.