Built on the site of Bridewell, a former 17th century house of correction, building started on Ruthin Gaol in 1775, with just four cells. By 1837 it held 37 inmates, and following the prisons act of 1865, a four-storey wing was built, mirroring the style of London’s Pentonville Prison. Ruthin became HM Prison Ruthin in 1878, and housed prisoners from counties Denbighshire, Flintshire, and Merionethshire.
There has been just one recorded execution at Ruthin. In 1903, William Hughes was hanged for the murder of his wife. Another character that stands out in Ruthin long history, is John Jones aka Coch Bach y Bala, a thief and a poacher, well known throughout many prisons in Wales and England. He managed to escape Ruthin Gaol twice throughout his incarceration. In 1879 he managed to walk straight out of the prison with a number of others whilst the guards were preoccupied with their suppers. A £5 reward was offered for any information that would lead to his capture, and as a result he was captured shortly after his escape.
His second escape was a little more daring, tunnelling out of his cell and escaping out of a window using bed sheets tied together to make a rope. 7 days on the run and living rough, he was eventually hunted down, and following a quick pursuit, one of the people chasing him shot John in the leg. He died from the wound shortly after, and the man who fired the shot was charged, however the charges were subsequently dropped later.
The building ceased being a prison in 1916, with prisoners and staff relocating to Shrewsbury. Denbighshire council purchased the building in 1926 and used it for offices, the country archives, and a library. Throughout World War II, a munitions factory operated there, before being handed back to the county council. They then used the building as a headquarters for the Denbighshire Library Service. 2002 was the next big change, when it was renovated and re-launched as a museum.