Go directly to Gaol

The Kilmainham Gaol or Jail was built west of Dublin in the early 19th century.  The first wing was dark and ominous, but later construction followed more enlightened goals of security, silence, and supervision, where a few guards could watch many prisoners easily yet insurrection was less likely.
All went well until the Great Potato Famine when jail with its steady rations held greater appeal than basic starvation, so folks crowded in.
The incarceration and executions of the individuals responsible for the Irish Revolution of 1916 make Kilmainham hallowed ground. Most faced firing squads and the prison was closed shortly after Irish independence.

Movie buffs will recognize Kilmainham from a wide variety of shows, most notably the original Italian Job.