A prison has been told it is not "providing a service fit for the 21st Century" for inmates or staff.
The "poor environment" at HMP Hewell, near Redditch in Worcestershire, is highlighted in the Independent Monitoring Board's (IMB) annual report.
Drug use is widespread, inmates have access to mobile phones and prisoners with disabilities are not catered for properly, the report said.
The Prisons Service said it was renovating facilities at the prison.
The annual report - for the period between October 2017 and September 2018 - said the inconsistent implementation of rules "allows a justified view by prisoners that they are sometimes treated unfairly".
It also found prisoners with disabilities were "inadequately catered for" and the access to illicit drugs and mobile phones "exacerbates the challenge of dealing with a largely transient prison population".
It said violence "remains an issue and has risen again towards the end of the reporting period".
Monitoring board chairman Roger Lawrence said: "The board recognises some areas of improvement since its last report but we remain disappointed that HMP Hewell does still not, in our view, provide a service fit for the 21st Century.
"The transient nature of much of the population at HMP Hewell presents barriers to meaningful rehabilitation."
The board noted improvements including the installation of the drone netting, the start of a window replacement and refurbishment programme and "a determination on the part of most staff to make HMP Hewell a safe and secure environment".
The category B jail opened in 2008 and holds more than 1,200 inmates.
A Prison Service spokesman said: "At HMP Hewell we are renovating existing facilities as well as upgrading security netting, cell windows, toilet and showering facilities - whiles working to identify more ways to improve the prison environment."
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