Barlinnie Prison wakes up quietly, at seven o'clock sharp. The staff check no-one's escaped or died. Then breakfast is served. 

Next on the menu, for almost a quarter of the inmates is methadone. The prison is the biggest dispenser of the heroin substitute in Europe. 

Barlinnie holds 1,664 inmates - the biggest jail population in Britain 

The jail dates back to the 1880s.  More than £18 million has been spent on improvements in the last decade.  The cells have toilets and TVs   

During stv's visit the infamous jail failed to live down to its reputation. It is no longer a brutal Victorian hellhole - but it is crammed to the seams - and that brings pressures everyone could do without. By 9pm, after a day free of incident, Barlinnie had gone to bed quietly and without a fuss.