 The prison was originally built in 1820 and opened as the Surrey House of Correction, Brixton Prison was intended to house 175 prisoners.However, regularly exceeding its capacity supporting over 200 prisoners, overcrowding was an early problem and with its small cells and poor living conditions contributed to its reputation as one of the worst prisons in London (worsened when Brixton became one of the first prisons to introduce treadwheels in 1821).There is an illustration of prisoners on the 1821 treadmill used to mill corn in Surrey House of Correction.