A drugs-ridden jail has continued to be overcrowded and unable to meet an "insatiable demand" for mental health support, prison monitors have said.
Up to 40% of cells designed for single inmates at HMP Hewell were housing two and conditions overall were "still not suitable for the 21st Century".
However some areas had improved at the Worcestershire prison, the Independent Monitoring Board (IMB), said.
The Ministry for Justice (MoJ) said the jail was within its capacity.
The jail, near Redditch in Worcestershire, was put in special measures by government inspectors in 2018.
It remains under those measures but within a new government-run scheme - the Prison Performance Support Programme (PPSP) - that was designed to help "challenging jails".
HMP Hewell had two prison sites - a male category B prison holding about 870 prisoners, and HMP Hewell Grange, an open prison that held about 200 prisoners before its closure earlier this year.
The government announced it was withdrawing HMP Hewell Grange from service in October last year after several critical reports, which included the chief inspector of prison describing conditions there as the worst he had ever seen.
In its annual report on the category B jail, the monitoring board said it had concerns about the frequency with which prisoners resorted to self-harm as a means of getting attention or treatment.
"Board members observe an almost insatiable demand for mental health care, with very limited resources available to meet it," the report said.
Staff were "largely inexperienced and often young" and working in "frequently unsafe circumstances".
Illicit use of drugs and mobile phones was also a concern, the report said.
IMB chair Rodger Lawrence said the board had seen improvements and determination to address challenges but remained "disappointed" by conditions for inmates that were "not conducive to their decent or humane treatment".
An MoJ spokesman said: "HMP Hewell remains within its operational capacity and the new X-ray body scanner will help improve safety and decency.
"Alongside this, we are creating 10,000 additional places - on top of the two new jails already being built."
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