Mountjoy Prison founded as Mountjoy Gaol, nicknamed The Joy, is a medium security prison

Prison

A prison is a place in which people are physically confined and, usually, deprived of a range of personal freedoms. Imprisonment or incarceration is a legal penalty that may be imposed by the state for the commission of a crime...

 located in Phibsboro

Phibsboro

Phibsborough , often formerly shortened to Phibsboro and later Phibsboro , is a district of Dublin in Ireland.-Location:Phibsboro' is located in the Dublin 7 postal district on the Northside of the city. The area is very close to the city centre, about two kilometres from the River Liffey which...

 in the centre of Dublin, Ireland

Ireland

Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

. It has the largest prison population in Ireland.

The current prison governor is Mr. Edward Whelan.
Mountjoy prison is constructed along a radial design with four main wings (A to D) each of which have three landings which are connected to a central circle.