You can lead a child to art but you'll have a terrible time trying to make him go inside. Not all the blandishments of a modern art gallery - shops, café and interactive displays that mean you don't even have to look at the damn pictures - will work if you have a pair of philistines like mine. Certainly not when you're in Brussels, which as far as those two are concerned is all about chocolate shops. So while my wife popped into the Musée Royaux des Beaux-Arts for Bosch and Brueghel, I frogmarched our barbarians back to the hotel past that obnoxious little Manneken Pis.
We were just turning into Rue de l'Etuve when I spotted something odd on the exposed gable end of a house. It was two men and a dog coming down a fire escape. "That's Tintin! " said John. And, indeed, it was. A life-sized Tintin, Captain Haddock and Snowy, all making their way down a two-dimensional fire escape that had been painted on to the side of the house.
Turning into Rue du Marché au Charbon, we saw another one. Not Tintin this time but a Richard Hannay-type character guarding a heroine in hat and gloves, painted on to the gable end of a bar. Strangely, the street behind our moustachioed cartoon hero in the mural was the exact same street that we were looking down now - but as it might have appeared 100 years ago. We were in effect looking at the same view twice, once in reality and once in a cartoon.
Across the road there was another huge mural. Down the side of a café someone had painted an aerial view of the road we were standing in with a cheerful character I recognised as "Broussaille", crossing it in the company of his girlfriend. In the background of the mural we could see the very building we were looking at now. It, too, had a mural painted on the wall above the cafe. For a moment I almost expected to see us standing in the cartoon staring up at the cartoon.
Fortunately our hotel was nearby and the helpful concierge had a leaflet that explained what was going on. Since 1991 the burghers of Brussels have been celebrating the fact that their city is the European capital of the "ninth art" via a series of murals on the gable ends of buildings.
I'd never heard of the ninth art but I did know that Belgium creates a huge amount of bandes dessinées, a phrase that takes in both the simple cartoon strip and its more adult cousin, the graphic novel. I'd even read Les Baleines publiques, the bizarre comic strip in which Brousaille wakes up to find whales swimming round Place de Brouckère in Brussels. The Tintin fire escape mural we'd seen had been painted in 2004 to commemorate the 75th anniversary of Belgium's most famous two-dimensional son.
Looking through the Cartoon Trail brochure we soon found that there are more than 30 of these huge cartoon images round the city, including Le Chat, my all-time favourite Belgian character. Created by Philippe Geluck in 1982, this stout besuited feline emanates a bizarre cross-eyed savoir faire. You either find him funny or you don't. We found him on the end of a house, not far from the Gare du Midi. We also found Cubitus in Rue de Flandre. Cubitus is a big jovial white dog. In this mural he has taken the place of Manneken Pis and is urinating away merrily with a big dopey smile on his face while that odious little boy looks on in surprise.
The way that these images often refer to the city where they were created builds their appeal and inevitably sent the three of us into a bande dessinée shop (there are scores) to look at the originals. I found that Brussels' gargantuan Palais de la Justice crops up in quite a few books. Gran' Place appears a lot too, including in Racing Show by Jean Graton. Our hotel, L'Amigo, also featured in that book in remarkably precise detail.
By this time we'd spent so long browsing that I felt we should all buy something. Liv came away with Le Code Zimmerman, the adventures of Victor Sackville, and John bought a beautifully crafted Obélix. Myself I was rather taken with a series of 6in topless Belgian nuns; very tasteful but somehow I couldn't see myself convincing my wife they were art.
THE COMPACT GUIDE
HOW TO GET THERE:
The Mourbys travelled as guests of Eurostar and Hotel Amigo. Eurostar (08705-186 186; eurostar. com) has return fares from London to Brussels from £59. Hotel Amigo (00 32 2 547 4747; hotelamigo.com), has doubles from €189 (£135).
Belgian Tourist Office (020-7531 0390; belgium theplacetobe.com).