The subterranean war tunnels beneath the Upper Barrakka saluting battery will be opened to the public for the first time in years to mark the feast of St Paul’s Shipwreck on Monday.

Speaking during a tour of ongoing restoration works, Fondazzjoni Wirt Artna director Mario Farrugia said the tunnels were a major strategic nerve centre during World War II.

The works, being carried out on the underground war headquarters and connecting tunnels beneath will return the subterranean maze to its original battle readiness.

The €2.3 million restoration works include repairs to damaged walls, the installation of a replica anti-gas attack ventilation system and the renovation of several original features.

While the winding underground passages were dug back in 1556, they were first used as strategic planning posts by the British in 1939.

This, Mr Farrugia said, was prompted by the Italian invasion of Ethiopia two years earlier. “The British feared the Italians might try to invade Malta, so they invested in protecting the island further,” he said.

The dark, damp rooms include several corporal dormitories and even one used by the commander of the Royal Air Force.

Restoration works are also being carried out on the counterguard along St Paul’s Bastions and the surrounding gardens.

Monday’s event will also feature a gun salute to mark the patron saint’s feast at midday and again at 4pm. Gun salutes were once commonplace for Catholic feasts on the island, with the Curia dishing out sizable donations for as many as 40 salutes on particular feasts.

There will also be a series of re-enactments on the saluting battery.

Mr Farrugia said this would be a journey through the bastion’s patronage under the Knights’, French and British occupations.

Children can attend the tour for free and adults will be charged €3.