The Kilmainham Gaol in Dublin is the largest unoccupied building of its kind in Europe. Opened in 1796, more than half of the prison’s original population was made up of debtors. Beggars, thieves, prostitutes, and drunks comprised the rest. Conditions were grim. Its first 50 years in existence, the building had no windows or lights; jailbirds were given one small candle every two weeks. Public hangings were common in the early 1800s, and during the Irish Famine (1845-50), the prison became so overcrowded, five people were locked in cells designed for one. Kilmainham closed in 1924 but now operates as a museum run by the Office of Public Works. An audio tour relays juicy details of its political and penal history, but just standing in silence in the eerie prison yard is enough to send chills down your spine.

The museum is open all year, save for December 24th-26th. Regular hours are 9:30 a.m. to 5:30 p.m. (last tour 4:15 p.m.); extended hours (9 a.m. to 6:45 p.m., with a last admission at 5:30 p.m.) are offered June 1 through August 31. Walk-up tours are 9 Euros ($10.62 USD) for adults; book online to save a Euro.

Inchicore Rd., Kilmainham, Dublin, Ireland; +353-1-453-5984.