By Oana Lungescu
BBC News, Brussels
The world's biggest collection of works by the Belgian surrealist Rene Magritte opens this week in his home city Brussels.
More than 40 years after his death, Magritte remains one of the most influential artists of the 20th Century.
His paintings have inspired pop and conceptual art, the cover of a Rolling Stones record, a video by Oasis, and songs by Paul Simon and John Cale.
Sir Paul McCartney is said to own several Magrittes.
The museum includes more than 100 paintings, a quarter of which come from private collections.
There's also a wealth of posters, photographs and home movies shot by Magritte.
It's expected to attract more than 600,000 visitors a year. But for one day only, last Saturday, some of them got a free ticket and a sneak preview.
Visitors got into the spirit of the occasion with the famous Magritte Blue
The square outside the museum, strategically placed between the Grand' Place and the Royal Palace, was renamed Magritte for the day.
Bowler hats and green apples - which often feature in his paintings - were on offer, while the windows of all the buildings in the square were covered with images of the typical Magritte sky, blue with white clouds.
In a typical Magritte twist, the sky over Brussels was clear and bright, as a group of people dressed in black descended on the square, twirling umbrellas and bowler hats as they danced past white pianos and sewing-machines.
It was a surrealist street party, a celebration for the most famous Belgian of them all.
"It's a special day," says a young man. "A special day for Belgium, a special day for Magritte and I like to be here today."
Waiting in a long line outside the museum, an American couple said they enjoyed Magritte's typically Belgian sense of humour where "things are not always as they seem".
A tall man, his face painted sky-blue with white clouds, had come from Mexico.
Magritte's personal trademark was the bowler hat
"Mexico is a venue for surrealism, because of Frida Kahlo and Diego Rivera and I like very much Magritte too," he said.
A newspaper boy distributed the first issue of the Magritte museum publication, shouting "this is not a newspaper! this is perhaps not a museum!" - a reference to one of the artist's most celebrated images, a pipe with the inscription "this is not a pipe".
Museum-visitors can hear an archive recording of Magritte's own explanation: "I don't see anything paradoxical in this image, because the image of a pipe is not a pipe.
"It may sound simplistic, but nonetheless that will shock people who've never considered this evidence."
In all his work, Rene Magritte (1898-1967) explored the mysterious relation between words and things, things and their image, the seen and the unseen.
He was influenced by popular art - from the slapstick of Laurel and Hardy to the detective novels of Dashiell Hammett - and started as a commercial artist, designing covers for sheet-music, posters and even wallpaper.
But in his paintings, he wanted to make people think about what he called "the mystery without which the world would not exist," by showing familiar objects in shocking or dreamlike surroundings.
To deepen that sense of mystery, the museum walls are painted in a deep dark colour, called "Magritte Blue," which was created especially from a mix of different shades in his paintings.
"We wanted to play with the light and to have the impression that the works are coming out from the night," explains the collection curator Virginie Devillez.
The impact of the paintings is heightened by the museum's sober lighting
Large paintings like The Empire of Lights seem to float towards you as you advance into the darkened space.
Like many Magritte works, it's a deceptively simple image of a white house, surrounded by tall trees and lit by a street-lamp at night. But look closer.
The house is set under a daytime sky, with a few white clouds. As Mrs Devillez explains, this disturbing juxtaposition of day and night is "an impossible image typical for Magritte".
Mrs Devillez dreams of one day exhibiting all 23 versions of The Empire of Lights in the museum.
It was so successful, especially with American collectors, that Magritte was commissioned to repaint it again and again.
His own life was a paradox. Despite being a communist supporter, he was also a salesman of his own work.
What interested him wasn't painting as such, but images and ideas.
Unlike his flamboyant friend Dali, Magritte lived what appeared to be an utterly conventional existence in a Brussels suburb.
His neighbours say he was polite and always wore a bowler hat when he took the dog out for a walk.
He never had a studio, but painted in his living-room, with his wife Georgette as the main model. They had met at a fair when he was 15 and she was 12.
You can visit the house, confusingly called the Rene Magritte Museum, if you take a tram just outside the new Magritte museum.
Magritte didn't actually like museums. After he briefly visited one in Florence he said: "It looks better on a postcard."
But the crowds in Brussels are clearly drawn to his new museum. It's a paradox that the artist would probably have enjoyed.