Visitors can step back in time in the fort’s network of underground tunnels and experience life as a Gravesend resident during the Second World War. There are also a number of guns on display that date from 1904 when the fort was rearmed due to the perceived threat from Germany. It was originally built during the1780s as part of the River Thames defence against a French naval attack, although its cannon were used to salute Louis VIII of France as he set off to reclaim his throne in 1814.