Building Britain (C4); Robinson Crusoe: The True Story (C4): EVERY cloud, so the more optimistic insist on saying, has a silver lining. Even the threat of nuclear war would have been good news for radio listeners.

After issuing the three-minute warning of nuclear attack, the BBC planned to play back-to-back episodes of The Archers. This would have been heaven for lovers of the Ambridge saga.

Dr Simon Thurley was full of such titbits of information in Building Britain, in which he aimed to show how the British character and its obsessions shaped the country's architecture.

As a nation, we've always been paranoid about being attacked, so no wonder politicians bang on about the fear factor all the time. The British have always spent more than anyone else on defences, most of which are never used.

As well as its castle, one of the mightiest fortresses in Western Europe, Dover boasts a massive artillery fort built in case Napoleon decided on a cross Channel invasion. He didn't, so troops used a triple staircase running from top to bottom to go to the pub instead.

Underneath the famous white cliffs of Dover, there's a honeycomb of secret tunnels and rooms to serve as the nerve centre of our coastal defences. Seven hundred military personnel lived and worked underground in complete secrecy during the Second World War.

Thurley visited the secret government HQ to be used in the event of a nuclear war. It's been abandoned for 30 years. He also told of the secret bunkers built to shelter those who would run the country after a nuclear attack.

Ironically, no-one would have lasted more than a few weeks as radiation would've seeped through the soft chalk of the cliffs.

Robinson Crusoe knew a thing or two about survival, although the real life Scot who inspired Daniel Defoe's classic novel wasn't as nice as his literary counterpart. Alexander Selkirk was a drinker and brawler from Fife - "a latterday football hooligan", his biographer Diana Souhami suggested.

This belligerent Scotsman ran away to sea at 15, became the ship's navigator and led a mutiny that resulted in him being thrown in the hold in irons. He demanded to be put off at the next desert island, only to find himself alone when none of his fellow sailors opted to leave the ship with him.

Wilderness expert Les Stroud was among contributors to Robinson Crusoe: The True Story and his job was to show how Selkirk coped with limited resources.

He wasn't entirely alone as his desert island was overrun with rats, who'd jumped ship earlier. Selkirk tamed the island's wild cats to help with his rat problem.

Goats played a key role in his survival and social life too. They provided food to eat, skins to wear and something to cuddle up to on cold nights. "The general feeling is that he had sex with goats," said one expert. He cut notches in their ears, presumably because no bedposts were available.

Eventually, castaway Selkirk was rescued, although he'd been away eight years by the time he reached home. He soon returned to his old bad boy ways, while Defoe set about writing his bestseller.

Robinson Crusoe is famous, Alexander Selkirk isn't. The final indignity is that the island on which Selkirk was cast away was renamed. They didn't called it Selkirk Island but Robinson Crusoe Island.

Published: 18/04/2005