By Dan Damon
Though they are both members of the European Union, the gloomy clang of a prison gate is a sound you are half as likely to hear in Denmark as in the UK.
Copenhagen's main prison is a sombre 19th Century building
While British judges lock up 139 people per 100,000 of population, in Denmark the figure is just over 60 - less than half.
Are Danes naturally so much less criminal, or are British criminals so tough they need locking up twice as often as the bad guys in Denmark?
Fewer people jailed
More family visits
Anger management courses
Comparing justice systems from one country to another is tricky, because there are so many other cultural and social factors affecting criminal behaviour.
But one figure does seem to stand out in comparisons of prison populations in Britain and Denmark.
While 55% of British prisoners will re-offend and come back to jail, in Denmark the re-offending rate is just 27%.
Copenhagen's main prison is a sombre 19th century building, with small cells and long, bleak linoleum halls.
Women guards are often better than men in calming down a prisoner who is getting angry
Anne Broendum, governor's office
Anne Broendum, a lawyer from the governor's office, showed me an empty cell.
It was small and there was a faint smell of urine.
There are no toilet facilities. Ms Broendum told me that just as in UK prisons of the same vintage, prisoners have to use a bucket and "slop out" in the morning.
"Or they do it in a plastic bag and throw it out of the window if they think they are waiting too long for the guard," she said with a resigned shrug.
Copenhagen's jail has other similar problems to many in the UK - including drugs, which are impossible to keep out with "a humane regime", according to Ms Broendum.
"We body search the prisoners after visits, but not the visitors."
So how does this jail, said to be the toughest in Denmark, keep the re-offending rate so low?
A clue comes in the number of female prison officers who patrol the corridors.
Many sentences in Denmark are for three months or less
About half of the officers are women.
"Women guards are often better than men in calming down a prisoner who is getting angry," said Ms Broendum.
"And the number of women helps the prisoners behave more normally. They don't just meet criminals and male guards, they interact with women."
That is a fundamental principle in Danish prison regimes - normalisation.
Annette Esdorf, deputy director general of the prison and probation service in Denmark, explains the philosophy.
"We make an effort to keep crime down by treating the prisoners in the best way. We have a rather humane regime, not because of the prisoners, but because we think it works better this way.
"Our prison regime is based on normalisation, a principle of openness and responsibility, because we think it's the best way of avoiding reconviction."
What about deterrence, retribution, the kinds of things British newspaper columnists are so keen on?
We have less crime than most European countries
Annette Esdorf, deputy director general of Danish prison and probation service
"We don't believe in that.
"Deterrence is not our policy. Instead, we have a tradition of short sentences, much shorter than in the UK or America.
"Only 15% of sentences are one year or more, more than half the sentences are three months or less."
Denmark releases prisoners early, allows them family visits, gives them education, training and anger management courses - all the things that appear "soft" to many in the UK.
So are the streets of Danish cities filled with criminals who should be in jail?
"Not at all," says Mrs Esdorf. "We have less crime than most European countries."
It would be hard to give conclusive proof that low prison numbers are a direct cause of low crime, but UK campaigners like Juliet Lyon of the Prison Reform Trust believe it is so.
"I visited two prisoners in British jails in the past couple of weeks. One was locked up for 22 hours a day, had no access to training, and was just being warehoused in the prison system," she said.
"Another, on a community punishment, was carefully supervised while living at home, and had to report to a drug treatment programme. His family are proud that at last he is getting out of the drug-and-crime cycle."
Back in Copenhagen prison, the inmates have just decorated one of the workshops. No girlie posters or violent film posters.
They put up Donald Duck and Mickey Mouse.
"It was their choice," said Ms Broendum.
It is hard to imagine a prison regime so successful it turns criminals into Disney fans.