The Three Musketeers at Fort Nelson

There is something naturally fitting about staging The Three Musketeers inside a Victorian fortress, and that is exactly the plan for a summer evening on Portsdown Hill. The Illyria Theatre Company brings its outdoor production to Fort Nelson on Friday 4 September, with the performance set on the fort's Parade Ground. It runs from 5:30pm to 8:00pm, so the curtain comes down well before it gets late, and the story follows the familiar path of D'Artagnan joining the King's Guard, with a good deal of the appeal riding on the swordplay. Tickets are £19.50 for adults and £10.84 for children.

The setting does a lot of the work here. Fort Nelson was built in the 1860s as part of the ring of forts designed to protect the port from a potential French invasion, which is a rather pointed backdrop for a story about French intrigue and royal guards. These days it is a national museum run by the Royal Armouries, and it holds more than 700 pieces of artillery covering 600 years of history. Among them are a 15th-century Turkish bombard cannon, a massive 200-tonne railway howitzer and the 'Big Babylon' Iraqi supergun. General admission to the museum is free, so there is no charge to wander the galleries before or after a show.

Illyria is an award-winning outdoor company that has been touring the UK for more than 30 years, and The Three Musketeers is part of a wider summer season that also takes Pinocchio, As You Like It and The Pirates of Penzance on the road. The production runs for about 135 minutes, including a 20-minute interval, and is aimed at ages 8 and up, though younger children are welcome if they are brave enough for it. If you are bringing younger ones, it is worth knowing that anyone 15 and under needs to be accompanied by a responsible adult at all times.

If you want to make a proper day of it, the fort is open during the school holidays from 23 July to 31 August, daily from 10am to 5pm, so you could visit the museum before the evening performance. There are free family activities on site, a café and a programme of exhibitions that changes regularly. Royal Armouries Members park for free, while everyone else pays for parking on arrival. Beyond the theatre, the fort keeps busy with other summer events: 'Summer at Fort Nelson' runs from 21 July to 6 September and is either free or £3.50, 'Defences & Discovery: Fort Nelson Revealed' falls on selected Wednesdays for £5, and the 'Outer Defences Tour' is scheduled for 19 September at £12. For a family evening out, though, the Musketeers on the Parade Ground is the obvious draw.