However, Molenbeek also has unemployment perhaps as high as 30 or 40 per cent, and an average income that lags far behind Belgium overall. It has more than its share of seedy blocks, shabby homes and bad schools. More importantly, perhaps, the neighbourhood stands in sharp contrast with the nearby wealthier residents of Brussels. And it is a 45-minute walk and a world away from the formidable buildings that are home to the European Union.
People who have studied Molenbeek say that the seeds of violent Islamic extremism were planted long ago.
"It doesn't surprise me because radical and political Islam in Belgium is something that grew up through the years," said Bilal Benyaich, a senior fellow and co-ordinator of studies on radical Islamists at a think-tank called the Itinera Institute.
"The fact that many people feel they will never make it, don't stand chance in society and envy others - this makes fertile grounds for recruiting."
Benyaich said that the Molenbeek residents receptive to calls to violence are a small minority, and "within this minority there is a group that can be activated by propaganda".
He noted that jihadist cells took root in Brussels back in the 1990s. Assailants with ties to Belgium played roles in the assassination of northern Afghan anti-Taliban leader Ahmed Shah Massoud, the 2004 Madrid bombings, the more recent Paris shootings at the magazine Charlie Hebdo and the attempt that young American off-duty soldiers thwarted on a high-speed train to Paris. Last year, the country was riveted by the trial of 46 people who were found guilty of belonging to Sharia4Belgium, a group that recruited volunteers to fight in Syria.
Belgium, on a per capita basis, has become the biggest exporter of fighters from Europe to Isis (Islamic State) in Syria. Nearly 500 people have left Belgium to fight for Isis. About 130 have come back, 77 have died fighting, and more than 200 remain on the field in Syria.
They emerged from an unusual social clash that has prevented Molenbeek from becoming a Belgian melting pot. Fifty years ago, a wave of immigrants came from Morocco and Turkey. Later, exiles from Libya and Egypt arrived. But in the 1970s, Benyaich said, Saudi Arabia and other Gulf countries sent funding for rigid religious schools, setting up tension between Wahabbi mosques and the more moderate and largely Moroccan tradition.
Today the neighbourhood has more than a dozen mosques, many of them tucked into old buildings. In some cases, more hardline Muslims took over the boards of existing mosques, Benyaich says.
Moreover, many jobs in Brussels require knowledge of French, Flemish or Dutch, and now sometimes English too while most immigrants speak mostly Arabic and some French. That has blocked integration. Flanders, by contrast, provides immigrants with language classes and courses about Belgian values.
Benyaich says that the Saudi message has played well to the children of immigrants who were suffering an identity crisis. And now Isis has stepped in and caught on.
Yannick Bochen, who runs a community centre in Molenbeek, says that the neighbourhood has never been treated equally. The violent extremists, though, don't represent Molenbeek. "It saddens me that it's Molenbeek again.
"I've been working in this community centre for six years," she said, "and a lot of people are really sick of this association."
The latest arrests have dealt that effort a heavy blow.
"In Molenbeek we do not have things under control at this moment," said the Interior Minister Jan Jambon said on TV. "There we need to make an extra effort."
While saying that "nothing justifies an act of barbarity" like that carried out in Paris, Benyaich also said "every society gets the radicals that it deserves. We created these monsters. Whether we like them or not they are still a product of our system."
