Clerkenwell Design Week allows the public rare access to the only remaining bits of Clerkenwell House of Detention, also known as the Middlesex House of Detention. They are the underground vaults, here pictured.
This institution was primarily a remand centre for prisoners awaiting trial at the nearby Middlesex Sessions House (still standing in largely original condition).
The main incident for which this prison is well-known, if at all, was a Fenian bomb attack on 13 December 1867. It became known as the Clerkenwell Outrage. The plan of this attack was to affect the escape of Fenian prisoners, primarily one Michael Blake. In addition to killing 12 bystanders, the attack was a fairly bodgy affair, with the perpetrators having to borrow matches for the purpose from some passing children. The ringleader, Michael Barrett, was found guilty of murder and became the last person to be publicly hanged at the notorious Newgate Prison, on 24 May 1868.
Both prisons were demolished in the years ahead, Clerkenwell in 1890 and Newgate in 1907.