After 53 years, BBC Television Centre is closing its doors for development at the end of this month. How will it be remembered?
With a design said to have been inspired by a question mark scribbled on the back of an envelope, BBC Television Centre is one of the UK's most recognisable cultural landmarks.
As a BBC handbook from 1960 points out, TV Centre was "the most up-to-date, self-contained broadcasting centre in Europe - the first in Britain to be designed specifically for television".
Some of the best-known programmes on British television were recorded within its walls: Dad's Army, I Claudius, Fawlty Towers, Top of the Pops, Monty Python's Flying Circus, The Two Ronnies, Blue Peter, classic era Doctor Who and Absolutely Fabulous.
The site sold for £200m last year, and will shut at the end of March to be redeveloped into a hotel, flats, a cinema and office space. The three main television studios will be refitted and leased out to production companies, including the BBC, from 2014.
The 14-acre site will also house the BBC's commercial arm, BBC Worldwide.
"This is a cathedral to the entertainment and news industry," said Esther Rantzen earlier this week. "It is a media cathedral. It's not just bricks and mortar."
Rantzen, who joined the BBC as a clerk in 1966 and worked as a researcher before achieving fame as the presenter of That's Life!, added: "I thought it was the most exciting set of gates ever to walk through. I knew this was a dream factory."
Madness will play live on Friday in front of the Grade II-listed building in west London. Broadcast live on BBC Four, the gig is followed by a two-hour show Goodbye Television Centre.
Hosted by former BBC chairman Michael Grade, the programme includes contributions from Sir David Attenborough, Sir Terry Wogan, Sir Michael Parkinson, Sir Bruce Forsyth, Sir David Jason, Penelope Keith and Ronnie Corbett.
But amid the strolls down memory lane, some voiced their regret over the closure. Sir Terry said: "I know it's only a building. I know it's an inanimate object and it doesn't have a heart.
"But it has a spirit. There are spirits here, of immensely talented, brilliant people who made some of the best television programmes ever seen and I think it's a shame. It's a shame to close it down."
The allegations of sexual abuse by presenter and DJ Jimmy Savile have also cast a shadow over the building's past.
"It's absolutely horrible. Ghastly. It's certainly a stain on the history of TV Centre. But it doesn't undermine the importance of TV Centre," Lord Grade told The Independent this week.
The former BBC One controller and director of programmes described the building as "the focal point for everything the BBC did best".
Back of an envelope
Designed by Graham Dawbarn, Television Centre was built in 1960 on the site of the Franco-British exhibition of 1908. Its distinctive circular main block - which housed the studios, dressing rooms and offices - was known to staff as the "doughnut".
The story goes that Dawbarn came up with idea in the pub after he drew the triangular shape of the building site on the back of an old envelope. Doodling a question mark in the middle, he realised it would make the perfect design.
Susan Hampshire was among the actors who came to know the studios well in the 1960s. In 1967 she starred in The Forsyte Saga, the last major drama to be shot in black and white; and Vanity Fair, the first to be made in colour.
"TV Centre had a family feeling. You walked along the corridor and everybody said hello," she recalled. "But all the corridors did look the same. We all got lost on our way to find the studio or the canteen.
"Unless you recognised someone in the costume from your period you had no idea where you were. All of us would end up in the wrong studios."
The people who never got lost were the BBC tour guides, who showed thousands of visitors around the building for more than a decade. "We knew those corridors pretty well," said Kelly Barnes, operations manager for BBC Tours.
TV Centre tours ended in February, but demand was so high in the final weeks that there were 18 separate tours running daily.
Visitors would get a close look at Gene Hunt's Audi Quattro from Life on Mars and the Tardis from Doctor Who. In the studio viewing galleries, they might glimpse rehearsals for shows like Strictly Come Dancing.
"Sometimes you'd catch sight of the dancers having a cigarette out in the hub in their dressing gowns," said Ms Barnes. "People loved seeing that it wasn't so glamorous behind the scenes.
"Most celebrities were really friendly, though occasionally you'd see them turn round and walk the other way. Once Ricky Tomlinson, from The Royle Family, came over and said hello, but the tour guide had to tell him the tour group were French and had no idea who he was!"
One of the last programmes to leave TV Centre has been quiz show Pointless, presented by Alexander Armstrong and Richard Osman.
"I know everything has to move on, but I'm glad there's been an outpouring of affection for TV Centre and an understanding of its place in the pantheon," said Osman, who is also creative director for independent production company Endemol UK.
Before its move to Elstree last month, Pointless was recorded at TC6, a studio that was also home to Tomorrow's World, Doctor Who, Only Fools and Horses, Fawlty Towers and Blue Peter.
"I was very sorry to leave," said Osman. "It's nice to have somewhere where everyone is working together on different shows and genres. There's something about an industry where everybody knows each other.
"Our camera supervisor, Nigel, had worked in TC6 for 30 years - his first ever show was in that studio making Top of the Pops. It was a place he'd put so much love into, along with so many other craftsmen and craftswomen who genuinely adore the place and adore their jobs.
"It all bleeds into the walls of the place. So many amazing comedy and entertainment shows have been made there.
"I think it's a terrible shame - it feels like they've closed down the Royal Opera House."