What life is like inside Brazil's most notorious and dangerous prison, the pictures below reveal.
At least 75 inmates have died in the Pedrinhas Prison Complex since 2013, National Council of Justice claims.
And three people were brutally beheaded in the complex that year during violent riots which claimed 60 lives.
Heavily armed military police keep a constant and watchful eye on the prisoners homed within the walls in Maranhao state.
However, it is not all men who are detained inside the prison, as it is home to female inmates - some of whom are heavily pregnant.