Cardiff prison disproves clichés that inner-city Victorian jails are “places of squalor, violence and despair”, the chief inspector of prisons has said.
It has also “bucked the national trend of rising violence” in other prisons and is safer now than three years ago.
But Peter Clarke issued a warning over the “extremely high figure” of 47% of inmates becoming homeless on release.
He called on the Welsh Government, prison and probation service to work together to find solutions.
On average more than 200 prisoners are released a month but nearly half do not have a home to go to, figures show.
Mr Clarke said there was a well established link between homelessness and re-offending and the issue at Cardiff was “striking”.
“I’ve spoken to prisoners, who’ve explained how, after being released without proper accommodation, they end up on the streets and inevitably the risks and vulnerabilities are far greater,” he said.
“I have therefore taken the unusual step of making a recommendation to both HM Prison and Probation Service (HMPPS) and the Welsh Government that they should work together to find solutions to this very serious problem.”