Children will love the challenge of the junior assault course, suitable for ages five to 11. Tickets cost £4.50 which you pay on the door.
Families will also be able to explore the 19-acre site with a free, interactive Fun at the Fort trail.
A special free exhibition Falklands 40 – What Portsmouth Saw – will continue to run through the school holidays featuring images from The News and BBC South footage of ships coming home to Portsmouth, as well as recordings of local veterans talking about the conflict.
Fort Nelson, on Portsdown hill is a fun day out for all the family – go and explore the Victorian fort with its tunnel, ramparts, and outdoor space, as well as a museum of treasures to discover.
There are lots of picnic benches around the site, and the café and refreshment kiosk will be open every day for light meals, snacks and drinks.
Events manager, Elizabeth Puddick, said: ‘It’s going to be an action-packed summer at Fort Nelson.
‘The assault course is always a big hit with the children, and they will enjoy the free trail too.
‘We’re really looking forward to giving our summer visitors a warm welcome to Fort Nelson.’
Summer activities will run daily from Wednesday July 20 to Sunday, September 4, and as a national museum, admission is to the fort is free. It is open daily, 10am to 5pm.
For more information go to royalarmouries.org.