I love Barlinnie. But only because I get to leave.

Bleak but beautiful, Scotland’s last Victorian prison can be as impressive for visitors as it is oppressive for inmates.

At its heart are five historic sandstone blocks, some of their masonry stained black with the soot of more than a century of Glasgow smog.

Each such rectangular unit - named A to E - has hanging baskets at its door. The plants, put there to offer some green in a black and grey world, somehow just underline how austere the structures are, like a flower in the barrel of a gun.

And yet these are striking rectangular structures. In another context they might be kirks or the halls of some great hydro-electric scheme. Purpose-built from 1882 to 1897, they are supposed to hold perhaps 200 men each. Barlinnie often caters for more.

Inside, once you get used to the sometimes rasping smell of jail, of a thousand men in close proximity, there is an almost sterilising bright light during the day.

It comes through skylights and huge Norman windows, a couple of stories high, above the doors. Brick walls, painted in thick white, like a trendy kitchen, scream “institution”.

No Scottish jail is a holiday camp. Forget tabloid stories of ‘soft touch’ justice. Our prisons, even new ones, are stark places. But Barlinnie is different.: this is the jail of population imagination. Cells are small, with a tiny TV, a bunk and, now, a toilet.

It is not long since inmates still slopped out, spending the night with their waste in a plastic container.

It’s not just the building that is historic conditions are too. Prisoners, in the coloured sweat shirts more normally seen on primary pupils, complain of a lack of opportunities for learning and leisure. Their jailors respond with the kind of authoritative banter that is somehow the preserve of Scottish police and prison officers.

Barlinnie does not define the Scottish Prison Service. Successive leaders have known it has to shut. Probably for housing, perhaps even for a museum, but not just of bad practice. It was here, in the Big Hoose’s Special Unit, that gangster Jimmy Boyle and others were rehabilitated, paving the way for a new better Scottish justice.