But without exception, at the same time everyday, it becomes a cage.

"Ten minutes until lockdown," blares across a nearby yard, where well-inked youngsters glide along a manicured running track and cluster around exercise equipment, or in shady corners.

Inside Nathan's* cell there's cheap instant coffee, a kettle and a prison regulation 34 centimetre television facing the head of a single bed.

The nostalgic sound of cartoons is blaring from a neighbouring cell, where somebody has abandoned a buttered piece of toast on a bed.

Nathan has just returned from work at the metal fabrication factory and he's joking about not getting time to tidy up. It's a single room, with its own curtained shower, toilet and sink.

Neatly arranged above the desk are magazine pictures of nameless women, motorcycles, and a single photograph.

This is not college, though, and at 8pm every night, Nathan's world shrinks to four claustrophobic walls, when the only links to the outside world are a TV and a photograph of a dog.

Melbourne's main remand prison for men runs under the philosophy that you truly are innocent until proven guilty, and about 1000 souls within its gates are not here to be punished.

They are awaiting their day in court and many have a powerful motivator for continued good behaviour on the inside: the prospect of bail, freedom.

Follow the stairs down from Nathan's cell and there's a bloke perched on a school-like chair, his face buried in the receiver of a wall-mounted telephone.  In a study room, an older man with bleary eyes is staring at a computer.

As Victoria's prison population has continued to grow, so too has the Metropolitan Remand Centre, which opened in 2006 with 600 beds but has already undergone a $65 million extension, increasing its capacity to tip 1000 last year.

Each of its dozen cell blocks are designed and resourced to meet the needs of their inhabitants, the drug addicts, the vulnerable, the mentally ill, the dangerous.

The Central Movement Control Hub, at the heart of the MRC, stares across the segregated blocks' fence-sketched yards, each with its own basketball court and running track, giving an insight into the sheer scale of the facility.

It is an impressive maximum security purgatory, 25 minutes west of the city.

Although most prisoners will only spend one to three months within these walls, for a very few this place will be their home for years.

*Not his real name.